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| author | Sverker Eriksson <[email protected]> | 2017-08-30 21:00:35 +0200 |
|---|---|---|
| committer | Sverker Eriksson <[email protected]> | 2017-08-30 21:00:35 +0200 |
| commit | 44a83c8860bbd00878c720a7b9d940b4630bab8a (patch) | |
| tree | 101b3c52ec505a94f56c8f70e078ecb8a2e8c6cd /lib/stdlib/doc/src | |
| parent | 7c67bbddb53c364086f66260701bc54a61c9659c (diff) | |
| parent | 040bdce67f88d833bfb59adae130a4ffb4c180f0 (diff) | |
| download | otp-44a83c8860bbd00878c720a7b9d940b4630bab8a.tar.gz otp-44a83c8860bbd00878c720a7b9d940b4630bab8a.tar.bz2 otp-44a83c8860bbd00878c720a7b9d940b4630bab8a.zip | |
Merge tag 'OTP-20.0' into sverker/20/binary_to_atom-utf8-crash/ERL-474/OTP-14590
Diffstat (limited to 'lib/stdlib/doc/src')
41 files changed, 3499 insertions, 1669 deletions
diff --git a/lib/stdlib/doc/src/assert_hrl.xml b/lib/stdlib/doc/src/assert_hrl.xml index e2dfc2ab9b..ea23cca2ee 100644 --- a/lib/stdlib/doc/src/assert_hrl.xml +++ b/lib/stdlib/doc/src/assert_hrl.xml @@ -4,7 +4,7 @@ <fileref> <header> <copyright> - <year>2012</year><year>2015</year> + <year>2012</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -28,7 +28,7 @@ <date></date> <rev></rev> </header> - <file>assert.hrl.xml</file> + <file>assert.hrl</file> <filesummary>Assert macros.</filesummary> <description> <p>The include file <c>assert.hrl</c> provides macros for inserting @@ -49,25 +49,33 @@ entries in the <c>Info</c> list are optional; do not rely programatically on any of them being present.</p> + <p>Each assert macro has a corresponding version with an extra argument, + for adding comments to assertions. These can for example be printed as + part of error reports, to clarify the meaning of the check that + failed. For example, <c>?assertEqual(0, fib(0), "Fibonacci is defined + for zero")</c>. The comment text can be any character data (string, + UTF8-binary, or deep list of such data), and will be included in the + error term as <c>{comment, Text}</c>.</p> + <p>If the macro <c>NOASSERT</c> is defined when <c>assert.hrl</c> is read by the compiler, the macros are defined as equivalent to the atom - <c>ok</c>. The test is not performed and there is no cost at runtime.</p> + <c>ok</c>. The test will not be performed and there is no cost at runtime.</p> <p>For example, using <c>erlc</c> to compile your modules, the following - disable all assertions:</p> + disables all assertions:</p> <code type="none"> erlc -DNOASSERT=true *.erl</code> - <p>The value of <c>NOASSERT</c> does not matter, only the fact that it is - defined.</p> + <p>(The value of <c>NOASSERT</c> does not matter, only the fact that it is + defined.)</p> <p>A few other macros also have effect on the enabling or disabling of assertions:</p> <list type="bulleted"> - <item><p>If <c>NODEBUG</c> is defined, it implies <c>NOASSERT</c>, unless - <c>DEBUG</c> is also defined, which is assumed to take precedence.</p> + <item><p>If <c>NODEBUG</c> is defined, it implies <c>NOASSERT</c> (unless + <c>DEBUG</c> is also defined, which overrides <c>NODEBUG</c>).</p> </item> <item><p>If <c>ASSERT</c> is defined, it overrides <c>NOASSERT</c>, that is, the assertions remain enabled.</p></item> @@ -84,16 +92,22 @@ erlc -DNOASSERT=true *.erl</code> <title>Macros</title> <taglist> <tag><c>assert(BoolExpr)</c></tag> + <item></item> + <tag><c>URKAassert(BoolExpr, Comment)</c></tag> <item> <p>Tests that <c>BoolExpr</c> completes normally returning <c>true</c>.</p> </item> <tag><c>assertNot(BoolExpr)</c></tag> + <item></item> + <tag><c>assertNot(BoolExpr, Comment)</c></tag> <item> <p>Tests that <c>BoolExpr</c> completes normally returning <c>false</c>.</p> </item> <tag><c>assertMatch(GuardedPattern, Expr)</c></tag> + <item></item> + <tag><c>assertMatch(GuardedPattern, Expr, Comment)</c></tag> <item> <p>Tests that <c>Expr</c> completes normally yielding a value that matches <c>GuardedPattern</c>, for example:</p> @@ -104,6 +118,8 @@ erlc -DNOASSERT=true *.erl</code> ?assertMatch({bork, X} when X > 0, f())</code> </item> <tag><c>assertNotMatch(GuardedPattern, Expr)</c></tag> + <item></item> + <tag><c>assertNotMatch(GuardedPattern, Expr, Comment)</c></tag> <item> <p>Tests that <c>Expr</c> completes normally yielding a value that does not match <c>GuardedPattern</c>.</p> @@ -111,16 +127,22 @@ erlc -DNOASSERT=true *.erl</code> <c>when</c> part.</p> </item> <tag><c>assertEqual(ExpectedValue, Expr)</c></tag> + <item></item> + <tag><c>assertEqual(ExpectedValue, Expr, Comment)</c></tag> <item> <p>Tests that <c>Expr</c> completes normally yielding a value that is exactly equal to <c>ExpectedValue</c>.</p> </item> <tag><c>assertNotEqual(ExpectedValue, Expr)</c></tag> + <item></item> + <tag><c>assertNotEqual(ExpectedValue, Expr, Comment)</c></tag> <item> <p>Tests that <c>Expr</c> completes normally yielding a value that is not exactly equal to <c>ExpectedValue</c>.</p> </item> <tag><c>assertException(Class, Term, Expr)</c></tag> + <item></item> + <tag><c>assertException(Class, Term, Expr, Comment)</c></tag> <item> <p>Tests that <c>Expr</c> completes abnormally with an exception of type <c>Class</c> and with the associated <c>Term</c>. The assertion fails @@ -130,6 +152,8 @@ erlc -DNOASSERT=true *.erl</code> patterns, as in <c>assertMatch</c>.</p> </item> <tag><c>assertNotException(Class, Term, Expr)</c></tag> + <item></item> + <tag><c>assertNotException(Class, Term, Expr, Comment)</c></tag> <item> <p>Tests that <c>Expr</c> does not evaluate abnormally with an exception of type <c>Class</c> and with the associated <c>Term</c>. @@ -139,14 +163,20 @@ erlc -DNOASSERT=true *.erl</code> be guarded patterns.</p> </item> <tag><c>assertError(Term, Expr)</c></tag> + <item></item> + <tag><c>assertError(Term, Expr, Comment)</c></tag> <item> <p>Equivalent to <c>assertException(error, Term, Expr)</c></p> </item> <tag><c>assertExit(Term, Expr)</c></tag> + <item></item> + <tag><c>assertExit(Term, Expr, Comment)</c></tag> <item> <p>Equivalent to <c>assertException(exit, Term, Expr)</c></p> </item> <tag><c>assertThrow(Term, Expr)</c></tag> + <item></item> + <tag><c>assertThrow(Term, Expr, Comment)</c></tag> <item> <p>Equivalent to <c>assertException(throw, Term, Expr)</c></p> </item> diff --git a/lib/stdlib/doc/src/beam_lib.xml b/lib/stdlib/doc/src/beam_lib.xml index d5ec90b060..26d0724aaf 100644 --- a/lib/stdlib/doc/src/beam_lib.xml +++ b/lib/stdlib/doc/src/beam_lib.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2000</year><year>2016</year> + <year>2000</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -42,10 +42,10 @@ and the corresponding identifiers are as follows:</p> <list type="bulleted"> - <item><c>abstract_code ("Abst")</c></item> <item><c>atoms ("Atom")</c></item> <item><c>attributes ("Attr")</c></item> <item><c>compile_info ("CInf")</c></item> + <item><c>debug_info ("Dbgi")</c></item> <item><c>exports ("ExpT")</c></item> <item><c>imports ("ImpT")</c></item> <item><c>indexed_imports ("ImpT")</c></item> @@ -60,9 +60,8 @@ <title>Debug Information/Abstract Code</title> <p>Option <c>debug_info</c> can be specified to the Compiler (see <seealso marker="compiler:compile#debug_info"><c>compile(3)</c></seealso>) - to have debug information in the form of abstract code (see section - <seealso marker="erts:absform">The Abstract Format</seealso> in the - ERTS User's Guide) stored in the <c>abstract_code</c> chunk. + to have debug information, such as <seealso marker="erts:absform">Erlang + Abstract Format</seealso>, stored in the <c>debug_info</c> chunk. Tools such as Debugger and Xref require the debug information to be included.</p> @@ -79,7 +78,7 @@ <section> <title>Reconstruct Source Code</title> - <p>The following example shows how to reconstruct source code from + <p>The following example shows how to reconstruct Erlang source code from the debug information in a BEAM file <c>Beam</c>:</p> <code type="none"> @@ -117,7 +116,7 @@ io:fwrite("~s~n", [erl_prettypr:format(erl_syntax:form_list(AC))]).</code> <list type="ordered"> <item> - <p>Use Compiler option <c>{debug_info,Key}</c>, see + <p>Use Compiler option <c>{debug_info_key,Key}</c>, see <seealso marker="compiler:compile#debug_info_key"><c>compile(3)</c></seealso> and function <seealso marker="#crypto_key_fun/1"><c>crypto_key_fun/1</c></seealso> @@ -198,18 +197,40 @@ io:fwrite("~s~n", [erl_prettypr:format(erl_syntax:form_list(AC))]).</code> <datatype> <name name="chunkid"/> <desc> - <p>"Abst" | "Attr" | "CInf" | "ExpT" | "ImpT" | "LocT" | "Atom"</p> + <p>"Attr" | "CInf" | "Dbgi" | "ExpT" | "ImpT" | "LocT" | "AtU8"</p> </desc> </datatype> <datatype> <name name="dataB"/> </datatype> <datatype> + <name name="debug_info"/> + <desc> + <p>The format stored in the <c>debug_info</c> chunk. + To retrieve particular code representation from the backend, + <c>Backend:debug_info(Format, Module, Data, Opts)</c> must be + invoked. <c>Format</c> is an atom, such as <c>erlang_v1</c> for + the Erlang Abstract Format or <c>core_v1</c> for Core Erlang. + <c>Module</c> is the module represented by the beam file and + <c>Data</c> is the value stored in the debug info chunk. + <c>Opts</c> is any list of values supported by the <c>Backend</c>. + <c>Backend:debug_info/4</c> must return <c>{ok, Code}</c> or + <c>{error, Term}</c>.</p> + + <p>Developers must always invoke the <c>debug_info/4</c> function + and never rely on the <c>Data</c> stored in the <c>debug_info</c> + chunk, as it is opaque and may change at any moment. <c>no_debug_info</c> + means that chunk <c>"Dbgi"</c> is present, but empty.</p> + </desc> + </datatype> + <datatype> <name name="abst_code"/> <desc> <p>It is not checked that the forms conform to the abstract format indicated by <c><anno>AbstVersion</anno></c>. <c>no_abstract_code</c> means that chunk <c>"Abst"</c> is present, but empty.</p> + <p>For modules compiled with OTP 20 onwards, the <c>abst_code</c> chunk + is automatically computed from the <c>debug_info</c> chunk.</p> </desc> </datatype> <datatype> @@ -346,7 +367,7 @@ io:fwrite("~s~n", [erl_prettypr:format(erl_syntax:form_list(AC))]).</code> <desc> <p>Registers an unary fun that is called if <c>beam_lib</c> must read an - <c>abstract_code</c> chunk that has been encrypted. The fun + <c>debug_info</c> chunk that has been encrypted. The fun is held in a process that is started by the function.</p> <p>If a fun is already registered when attempting to register a fun, <c>{error, exists}</c> is returned.</p> @@ -443,7 +464,8 @@ CryptoKeyFun(clear) -> term()</code> <desc> <p>Removes all chunks from a BEAM file except those needed by the loader. In particular, - the debug information (chunk <c>abstract_code</c>) is removed.</p> + the debug information (chunk <c>debug_info</c> and <c>abstract_code</c>) + is removed.</p> </desc> </func> @@ -454,9 +476,9 @@ CryptoKeyFun(clear) -> term()</code> <desc> <p>Removes all chunks except those needed by the loader from BEAM files. In particular, - the debug information (chunk <c>abstract_code</c>) is removed. - The returned list contains one element for each specified filename, - in the same order as in <c>Files</c>.</p> + the debug information (chunk <c>debug_info</c> and <c>abstract_code</c>) + is removed. The returned list contains one element for each + specified filename, in the same order as in <c>Files</c>.</p> </desc> </func> diff --git a/lib/stdlib/doc/src/c.xml b/lib/stdlib/doc/src/c.xml index 92ab59c6b0..7666699183 100644 --- a/lib/stdlib/doc/src/c.xml +++ b/lib/stdlib/doc/src/c.xml @@ -52,13 +52,27 @@ <func> <name name="c" arity="1"/> <name name="c" arity="2"/> - <fsummary>Compile and load code in a file.</fsummary> + <name name="c" arity="3"/> + <fsummary>Compile and load a file or module.</fsummary> <desc> - <p>Compiles and then purges and loads the code for a file. - <c><anno>Options</anno></c> defaults to <c>[]</c>. Compilation is - equivalent to:</p> - <code type="none"> -compile:file(<anno>File</anno>, <anno>Options</anno> ++ [report_errors, report_warnings])</code> + <p>Compiles and then purges and loads the code for a module. + <c><anno>Module</anno></c> can be either a module name or a source + file path, with or without <c>.erl</c> extension. + <c><anno>Options</anno></c> defaults to <c>[]</c>.</p> + <p>If <c><anno>Module</anno></c> is an atom and is not the path of a + source file, then the code path is searched to locate the object + file for the module and extract its original compiler options and + source path. If the source file is not found in the original + location, <seealso + marker="filelib#find_source/1"><c>filelib:find_source/1</c></seealso> + is used to search for it relative to the directory of the object + file.</p> + <p>The source file is compiled with the the original + options appended to the given <c><anno>Options</anno></c>, the + output replacing the old object file if and only if compilation + succeeds. A function <c><anno>Filter</anno></c> can be specified + for removing elements from from the original compiler options + before the new options are added.</p> <p>Notice that purging the code means that any processes lingering in old code for the module are killed without warning. For more information, see <c>code/3</c>.</p> @@ -148,6 +162,15 @@ compile:file(<anno>File</anno>, <anno>Options</anno> ++ [report_errors, report_w </func> <func> + <name name="lm" arity="0"/> + <fsummary>Loads all modified modules.</fsummary> + <desc> + <p>Reloads all currently loaded modules that have changed on disk (see <c>mm()</c>). + Returns the list of results from calling <c>l(M)</c> for each such <c>M</c>.</p> + </desc> + </func> + + <func> <name name="ls" arity="0"/> <fsummary>List files in the current directory.</fsummary> <desc> @@ -182,6 +205,15 @@ compile:file(<anno>File</anno>, <anno>Options</anno> ++ [report_errors, report_w </func> <func> + <name name="mm" arity="0"/> + <fsummary>Lists all modified modules.</fsummary> + <desc> + <p>Lists all modified modules. Shorthand for + <seealso marker="kernel:code#modified_modules/0"><c>code:modified_modules/0</c></seealso>.</p> + </desc> + </func> + + <func> <name name="memory" arity="0"/> <fsummary>Memory allocation information.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/dets.xml b/lib/stdlib/doc/src/dets.xml index 3b134d00b7..eb6e32aecf 100644 --- a/lib/stdlib/doc/src/dets.xml +++ b/lib/stdlib/doc/src/dets.xml @@ -100,18 +100,12 @@ provided by Dets, neither is the limited support for concurrent updates that makes a sequence of <c>first</c> and <c>next</c> calls safe to use on fixed ETS tables. Both these - features will be provided by Dets in a future release of + features may be provided by Dets in a future release of Erlang/OTP. Until then, the Mnesia application (or some user-implemented method for locking) must be used to implement safe concurrency. Currently, no Erlang/OTP library has support for ordered disk-based term storage.</p> - <p>Two versions of the format used for storing objects on file are - supported by Dets. The first version, 8, is the format always used - for tables created by Erlang/OTP R7 and earlier. The second version, 9, - is the default version of tables created by Erlang/OTP R8 (and later - releases). Erlang/OTP R8 can create version 8 tables, and convert version - 8 tables to version 9, and conversely, upon request.</p> <p>All Dets functions return <c>{error, Reason}</c> if an error occurs (<seealso marker="#first/1"><c>first/1</c></seealso> and <seealso marker="#next/2"><c>next/2</c></seealso> are exceptions, they @@ -190,9 +184,6 @@ <datatype> <name name="type"/> </datatype> - <datatype> - <name name="version"/> - </datatype> </datatypes> <funcs> @@ -385,19 +376,14 @@ <p><c>{bchunk_format, binary()}</c> - An opaque binary describing the format of the objects returned by <c>bchunk/2</c>. The binary can be used as argument to - <c>is_compatible_chunk_format/2</c>. Only available for - version 9 tables.</p> + <c>is_compatible_chunk_format/2</c>.</p> </item> <item> <p><c>{hash, Hash}</c> - Describes which BIF is used to calculate the hash values of the objects stored in the - <c>dets</c> table. Possible values of <c>Hash</c>:</p> + Dets table. Possible values of <c>Hash</c>:</p> <list> <item> - <p><c>hash</c> - Implies that the <c>erlang:hash/2</c> BIF - is used.</p> - </item> - <item> <p><c>phash</c> - Implies that the <c>erlang:phash/2</c> BIF is used.</p> </item> @@ -413,8 +399,7 @@ </item> <item> <p><c>{no_keys, integer >= 0()}</c> - The number of different - keys stored in the table. Only available for version 9 - tables.</p> + keys stored in the table.</p> </item> <item> <p><c>{no_objects, integer >= 0()}</c> - The number of objects @@ -424,8 +409,7 @@ <p><c>{no_slots, {Min, Used, Max}}</c> - The number of slots of the table. <c>Min</c> is the minimum number of slots, <c>Used</c> is the number of currently used slots, - and <c>Max</c> is the maximum number of slots. Only - available for version 9 tables.</p> + and <c>Max</c> is the maximum number of slots.</p> </item> <item> <p><c>{owner, pid()}</c> - The pid of the process that @@ -466,10 +450,6 @@ time warp safe</seealso>. Time warp safe code must use <c>safe_fixed_monotonic_time</c> instead.</p> </item> - <item> - <p><c>{version, integer()}</c> - The version of the format of - the table.</p> - </item> </list> </desc> </func> @@ -662,8 +642,8 @@ ok objects at a time, until at least one object matches or the end of the table is reached. The default, indicated by giving <c><anno>N</anno></c> the value <c>default</c>, is to let - the number of objects vary depending on the sizes of the objects. If - <c><anno>Name</anno></c> is a version 9 table, all objects with the + the number of objects vary depending on the sizes of the objects. + All objects with the same key are always matched at the same time, which implies that more than <anno>N</anno> objects can sometimes be matched.</p> <p>The table is always to be protected using @@ -743,9 +723,9 @@ ok end of the table is reached. The default, indicated by giving <c><anno>N</anno></c> the value <c>default</c>, is to let the number - of objects vary depending on the sizes of the objects. If - <c><anno>Name</anno></c> is a version 9 table, all matching objects - with the same key are always returned in the same reply, which implies + of objects vary depending on the sizes of the objects. All + matching objects with the same key are always returned + in the same reply, which implies that more than <anno>N</anno> objects can sometimes be returned.</p> <p>The table is always to be protected using <seealso marker="#safe_fixtable/2"><c>safe_fixtable/2</c></seealso> @@ -842,8 +822,7 @@ ok maximal value. Notice that a higher value can increase the table fragmentation, and a smaller value can decrease the fragmentation, at - the expense of execution time. Only available for version - 9 tables.</p> + the expense of execution time.</p> </item> <item> <p><c>{min_no_slots, </c><seealso marker="#type-no_slots"> @@ -880,12 +859,7 @@ ok FileName}}</c> is returned if the table must be repaired.</p> <p>Value <c>force</c> means that a reparation is made even if the table is properly closed. - This is how to convert tables created by older versions of - STDLIB. An example is tables hashed with the deprecated - <c>erlang:hash/2</c> BIF. Tables created with Dets from - STDLIB version 1.8.2 or later use function - <c>erlang:phash/2</c> or function <c>erlang:phash2/1</c>, - which is preferred.</p> + This is a seldom needed option.</p> <p>Option <c>repair</c> is ignored if the table is already open.</p> </item> <item> @@ -893,15 +867,6 @@ ok <c>type()</c></seealso><c>}</c> - The table type. Defaults to <c>set</c>.</p> </item> - <item> - <p><c>{version, </c><seealso marker="#type-version"> - <c>version()</c></seealso><c>}</c> - The version of the format - used for the table. Defaults to <c>9</c>. Tables on the format - used before Erlang/OTP R8 can be created by specifying value - <c>8</c>. A version 8 table can be converted to a version 9 - table by specifying options <c>{version,9}</c> - and <c>{repair,force}</c>.</p> - </item> </list> </desc> </func> @@ -1041,8 +1006,8 @@ ok a time, until at least one object matches or the end of the table is reached. The default, indicated by giving <c><anno>N</anno></c> the value <c>default</c>, is to let the number - of objects vary depending on the sizes of the objects. If - <c><anno>Name</anno></c> is a version 9 table, all objects with the + of objects vary depending on the sizes of the objects. All + objects with the same key are always handled at the same time, which implies that the match specification can be applied to more than <anno>N</anno> objects.</p> diff --git a/lib/stdlib/doc/src/dict.xml b/lib/stdlib/doc/src/dict.xml index c926ff1b5b..c229a18721 100644 --- a/lib/stdlib/doc/src/dict.xml +++ b/lib/stdlib/doc/src/dict.xml @@ -106,6 +106,16 @@ </func> <func> + <name name="take" arity="2"/> + <fsummary>Return value and new dictionary without element with this value.</fsummary> + <desc> + <p>This function returns value from dictionary and a + new dictionary without this value. + Returns <c>error</c> if the key is not present in the dictionary.</p> + </desc> + </func> + + <func> <name name="filter" arity="2"/> <fsummary>Select elements that satisfy a predicate.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/erl_expand_records.xml b/lib/stdlib/doc/src/erl_expand_records.xml index 7e4aa2db37..b6aa75ed03 100644 --- a/lib/stdlib/doc/src/erl_expand_records.xml +++ b/lib/stdlib/doc/src/erl_expand_records.xml @@ -45,8 +45,10 @@ <name name="module" arity="2"/> <fsummary>Expand all records in a module.</fsummary> <desc> - <p>Expands all records in a module. The returned module has no - references to records, attributes, or code.</p> + <p>Expands all records in a module to use explicit tuple + operations and adds explicit module names to calls to BIFs and + imported functions. The returned module has no references to + records, attributes, or code.</p> </desc> </func> </funcs> diff --git a/lib/stdlib/doc/src/erl_internal.xml b/lib/stdlib/doc/src/erl_internal.xml index cf49df0972..17cd0fb240 100644 --- a/lib/stdlib/doc/src/erl_internal.xml +++ b/lib/stdlib/doc/src/erl_internal.xml @@ -44,6 +44,16 @@ <funcs> <func> + <name name="add_predefined_functions" arity="1"/> + <fsummary>Add code for pre-defined functions.</fsummary> + <desc> + <p>Adds to <c><anno>Forms</anno></c> the code for the standard + pre-defined functions (such as <c>module_info/0</c>) that are + to be included in every module.</p> + </desc> + </func> + + <func> <name name="arith_op" arity="2"/> <fsummary>Test for an arithmetic operator.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/erl_tar.xml b/lib/stdlib/doc/src/erl_tar.xml index 24e7b64b9e..337028568a 100644 --- a/lib/stdlib/doc/src/erl_tar.xml +++ b/lib/stdlib/doc/src/erl_tar.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2003</year><year>2016</year> + <year>2003</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -37,12 +37,13 @@ </modulesummary> <description> <p>This module archives and extract files to and from - a tar file. This module supports the <c>ustar</c> format - (IEEE Std 1003.1 and ISO/IEC 9945-1). All modern <c>tar</c> - programs (including GNU tar) can read this format. To ensure that - that GNU tar produces a tar file that <c>erl_tar</c> can read, - specify option <c>--format=ustar</c> to GNU tar.</p> - + a tar file. This module supports reading most common tar formats, + namely v7, STAR, USTAR, and PAX, as well as some of GNU tar's extensions + to the USTAR format (sparse files most notably). It produces tar archives + in USTAR format, unless the files being archived require PAX format due to + restrictions in USTAR (such as unicode metadata, filename length, and more). + As such, <c>erl_tar</c> supports tar archives produced by most all modern + tar utilities, and produces tarballs which should be similarly portable.</p> <p>By convention, the name of a tar file is to end in "<c>.tar</c>". To abide to the convention, add "<c>.tar</c>" to the name.</p> @@ -83,6 +84,8 @@ <p>If <seealso marker="kernel:file#native_name_encoding/0"> <c>file:native_name_encoding/0</c></seealso> returns <c>latin1</c>, no translation of path names is done.</p> + + <p>Unicode metadata stored in PAX headers is preserved</p> </section> <section> @@ -104,21 +107,20 @@ <title>Limitations</title> <list type="bulleted"> <item> - <p>For maximum compatibility, it is safe to archive files with names - up to 100 characters in length. Such tar files can generally be - extracted by any <c>tar</c> program.</p> - </item> - <item> - <p>For filenames exceeding 100 characters in length, the resulting tar - file can only be correctly extracted by a POSIX-compatible <c>tar</c> - program (such as Solaris <c>tar</c> or a modern GNU <c>tar</c>).</p> - </item> - <item> - <p>Files with longer names than 256 bytes cannot be stored.</p> + <p>If you must remain compatible with the USTAR tar format, you must ensure file paths being + stored are less than 255 bytes in total, with a maximum filename component + length of 100 bytes. USTAR uses a header field (prefix) in addition to the name field, and + splits file paths longer than 100 bytes into two parts. This split is done on a directory boundary, + and is done in such a way to make the best use of the space available in those two fields, but in practice + this will often mean that you have less than 255 bytes for a path. <c>erl_tar</c> will + automatically upgrade the format to PAX to handle longer filenames, so this is only an issue if you + need to extract the archive with an older implementation of <c>erl_tar</c> or <c>tar</c> which does + not support PAX. In this case, the PAX headers will be extracted as regular files, and you will need to + apply them manually.</p> </item> <item> - <p>The file name a symbolic link points is always limited - to 100 characters.</p> + <p>Like the above, if you must remain USTAR compatible, you must also ensure than paths for + symbolic/hard links are no more than 100 bytes, otherwise PAX headers will be used.</p> </item> </list> </section> @@ -129,7 +131,9 @@ <fsummary>Add a file to an open tar file.</fsummary> <type> <v>TarDescriptor = term()</v> - <v>Filename = filename()</v> + <v>FilenameOrBin = filename()|binary()</v> + <v>NameInArchive = filename()</v> + <v>Filename = filename()|{NameInArchive,FilenameOrBin}</v> <v>Options = [Option]</v> <v>Option = dereference|verbose|{chunks,ChunkSize}</v> <v>ChunkSize = positive_integer()</v> @@ -139,6 +143,9 @@ <desc> <p>Adds a file to a tar file that has been opened for writing by <seealso marker="#open/2"><c>open/1</c></seealso>.</p> + <p><c>NameInArchive</c> is the name under which the file becomes + stored in the tar file. The file gets this name when it is + extracted from the tar file.</p> <p>Options:</p> <taglist> <tag><c>dereference</c></tag> @@ -183,9 +190,6 @@ <seealso marker="#open/2"><c>open/2</c></seealso>. This function accepts the same options as <seealso marker="#add/3"><c>add/3</c></seealso>.</p> - <p><c>NameInArchive</c> is the name under which the file becomes - stored in the tar file. The file gets this name when it is - extracted from the tar file.</p> </desc> </func> @@ -206,8 +210,8 @@ <fsummary>Create a tar archive.</fsummary> <type> <v>Name = filename()</v> - <v>FileList = [Filename|{NameInArchive, binary()},{NameInArchive, - Filename}]</v> + <v>FileList = [Filename|{NameInArchive, FilenameOrBin}]</v> + <v>FilenameOrBin = filename()|binary()</v> <v>Filename = filename()</v> <v>NameInArchive = filename()</v> <v>RetValue = ok|{error,{Name,Reason}}</v> @@ -225,8 +229,8 @@ <fsummary>Create a tar archive with options.</fsummary> <type> <v>Name = filename()</v> - <v>FileList = [Filename|{NameInArchive, binary()},{NameInArchive, - Filename}]</v> + <v>FileList = [Filename|{NameInArchive, FilenameOrBin}]</v> + <v>FilenameOrBin = filename()|binary()</v> <v>Filename = filename()</v> <v>NameInArchive = filename()</v> <v>OptionList = [Option]</v> @@ -275,7 +279,8 @@ <name>extract(Name) -> RetValue</name> <fsummary>Extract all files from a tar file.</fsummary> <type> - <v>Name = filename()</v> + <v>Name = filename() | {binary,binary()} | {file,Fd}</v> + <v>Fd = file_descriptor()</v> <v>RetValue = ok|{error,{Name,Reason}}</v> <v>Reason = term()</v> </type> @@ -287,6 +292,10 @@ <c>Fd</c> is assumed to be a file descriptor returned from function <c>file:open/2</c>.</p> <p>Otherwise, <c>Name</c> is to be a filename.</p> + <note><p>Leading slashes in tar member names will be removed before + writing the file. That is, absolute paths will be turned into + relative paths. There will be an info message written to the error + logger when paths are changed in this way.</p></note> </desc> </func> @@ -294,8 +303,7 @@ <name>extract(Name, OptionList)</name> <fsummary>Extract files from a tar file.</fsummary> <type> - <v>Name = filename() | {binary,Binary} | {file,Fd}</v> - <v>Binary = binary()</v> + <v>Name = filename() | {binary,binary()} | {file,Fd}</v> <v>Fd = file_descriptor()</v> <v>OptionList = [Option]</v> <v>Option = {cwd,Cwd}|{files,FileList}|keep_old_files|verbose|memory</v> @@ -521,7 +529,7 @@ erl_tar:close(TarDesc)</code> <name>table(Name) -> RetValue</name> <fsummary>Retrieve the name of all files in a tar file.</fsummary> <type> - <v>Name = filename()</v> + <v>Name = filename()|{binary,binary()}|{file,file_descriptor()}</v> <v>RetValue = {ok,[string()]}|{error,{Name,Reason}}</v> <v>Reason = term()</v> </type> @@ -535,7 +543,7 @@ erl_tar:close(TarDesc)</code> <fsummary>Retrieve name and information of all files in a tar file. </fsummary> <type> - <v>Name = filename()</v> + <v>Name = filename()|{binary,binary()}|{file,file_descriptor()}</v> </type> <desc> <p>Retrieves the names of all files in the tar file <c>Name</c>.</p> @@ -546,7 +554,7 @@ erl_tar:close(TarDesc)</code> <name>t(Name)</name> <fsummary>Print the name of each file in a tar file.</fsummary> <type> - <v>Name = filename()</v> + <v>Name = filename()|{binary,binary()}|{file,file_descriptor()}</v> </type> <desc> <p>Prints the names of all files in the tar file <c>Name</c> to the @@ -559,7 +567,7 @@ erl_tar:close(TarDesc)</code> <fsummary>Print name and information for each file in a tar file. </fsummary> <type> - <v>Name = filename()</v> + <v>Name = filename()|{binary,binary()}|{file,file_descriptor()}</v> </type> <desc> <p>Prints names and information about all files in the tar file diff --git a/lib/stdlib/doc/src/ets.xml b/lib/stdlib/doc/src/ets.xml index b8e262208d..f6f3d18d6a 100644 --- a/lib/stdlib/doc/src/ets.xml +++ b/lib/stdlib/doc/src/ets.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -49,13 +49,22 @@ associated with each key. A <c>bag</c> or <c>duplicate_bag</c> table can have many objects associated with each key.</p> - <p>The number of tables stored at one Erlang node is limited. - The current default limit is about 1400 tables. The upper - limit can be increased by setting environment variable - <c>ERL_MAX_ETS_TABLES</c> before starting the Erlang runtime - system (that is, with option <c>-env</c> to - <c>erl</c>/<c>werl</c>). The actual limit can be slightly higher - than the one specified, but never lower.</p> + <note> + <p> + The number of tables stored at one Erlang node <em>used</em> to + be limited. This is no longer the case (except by memory usage). + The previous default limit was about 1400 tables and + could be increased by setting the environment variable + <c>ERL_MAX_ETS_TABLES</c> before starting the Erlang runtime + system. This hard limit has been removed, but it is currently + useful to set the <c>ERL_MAX_ETS_TABLES</c> anyway. It should be + set to an approximate of the maximum amount of tables used. This since + an internal table for named tables is sized using this value. If + large amounts of named tables are used and <c>ERL_MAX_ETS_TABLES</c> + hasn't been increased, the performance of named table lookup will + degrade. + </p> + </note> <p>Notice that there is no automatic garbage collection for tables. Even if there are no references to a table from any process, it @@ -369,7 +378,7 @@ variable that in turn is passed to the function.</p> <p>The parse transform is provided in the <c>ms_transform</c> module and the source <em>must</em> include - file <c>ms_transform.hrl</c> in <c>STDLIB</c> for this + file <c>ms_transform.hrl</c> in STDLIB for this pseudo function to work. Failing to include the hrl file in the source results in a runtime error, not a compile time error. The include file is easiest included by adding line @@ -541,10 +550,6 @@ Error: fun containing local Erlang function calls <c><anno>Tab</anno></c> is not of the correct type, or if <c><anno>Item</anno></c> is not one of the allowed values, a <c>badarg</c> exception is raised.</p> - <warning> - <p>In Erlang/OTP R11B and earlier, this function would not fail but - return <c>undefined</c> for invalid values for <c>Item</c>.</p> - </warning> <p>In addition to the <c>{<anno>Item</anno>,<anno>Value</anno>}</c> pairs defined for <seealso marker="#info/1"><c>info/1</c></seealso>, the following items are allowed:</p> @@ -1458,7 +1463,7 @@ is_integer(X), is_integer(Y), X + Y < 4711]]></code> specification returned <c>true</c>.</fsummary> <desc> <p>Matches the objects in table <c><anno>Tab</anno></c> using a - <seealso marker="#match_spec">match specificationc</seealso>. If the + <seealso marker="#match_spec">match specification</seealso>. If the match specification returns <c>true</c> for an object, that object considered a match and is counted. For any other result from the match specification the object is not considered a match and is @@ -1495,6 +1500,45 @@ is_integer(X), is_integer(Y), X + Y < 4711]]></code> </func> <func> + <name name="select_replace" arity="2"/> + <fsummary>Match and replace objects atomically in an ETS table</fsummary> + <desc> + <p>Matches the objects in the table <c><anno>Tab</anno></c> using a + <seealso marker="#match_spec">match specification</seealso>. For each + matched object, the existing object is replaced with + the match specification result.</p> + <p>The match-and-replace operation for each individual object is guaranteed to be + <seealso marker="#concurrency">atomic and isolated</seealso>. The + <c>select_replace</c> table iteration as a whole, like all other select functions, + does not give such guarantees.</p> + <p>The match specifiction must be guaranteed to <em>retain the key</em> + of any matched object. If not, <c>select_replace</c> will fail with <c>badarg</c> + without updating any objects.</p> + <p>For the moment, due to performance and semantic constraints, + tables of type <c>bag</c> are not yet supported.</p> + <p>The function returns the total number of replaced objects.</p> + <p><em>Example</em></p> + <p>For all 2-tuples with a list in second position, add atom <c>'marker'</c> first in the list:</p> + <pre> +1> <input>T = ets:new(x,[]), ets:insert(T, {key, [1, 2, 3]}).</input> +true +2> <input>MS = ets:fun2ms(fun({K, L}) when is_list(L) -> {K, [marker | L]} end).</input> +[{{'$1','$2'},[{is_list,'$2'}],[{{'$1',[marker|'$2']}}]}] +3> <input>ets:select_replace(T, MS).</input> +1 +4> <input>ets:tab2list(T).</input> +[{key,[marker,1,2,3]}] + </pre> + <p>A generic single object compare-and-swap operation:</p> + <pre> +[Old] = ets:lookup(T, Key), +New = update_object(Old), +Success = (1 =:= ets:select_replace(T, [{Old, [], [{const, New}]}])), + </pre> + </desc> + </func> + + <func> <name name="select_reverse" arity="1"/> <fsummary>Continue matching objects in an ETS table.</fsummary> <desc> @@ -1644,7 +1688,7 @@ is_integer(X), is_integer(Y), X + Y < 4711]]></code> </taglist> <p>Whenever option <c>extended_info</c> is used, it results in a file not readable by versions of ETS before - that in <c>STDLIB</c> 1.15.1</p> + that in STDLIB 1.15.1</p> <p>If option <c>sync</c> is set to <c>true</c>, it ensures that the content of the file is written to the disk before <c>tab2file</c> returns. Defaults to <c>{sync, false}</c>.</p> @@ -1725,7 +1769,7 @@ is_integer(X), is_integer(Y), X + Y < 4711]]></code> <p>A tuple <c>{<anno>Major</anno>,<anno>Minor</anno>}</c> containing the major and minor version of the file format for ETS table dumps. This - version field was added beginning with <c>STDLIB</c> 1.5.1. + version field was added beginning with STDLIB 1.5.1. Files dumped with older versions return <c>{0,0}</c> in this field.</p> </item> diff --git a/lib/stdlib/doc/src/filelib.xml b/lib/stdlib/doc/src/filelib.xml index 7c6380ce28..80c4acffdb 100644 --- a/lib/stdlib/doc/src/filelib.xml +++ b/lib/stdlib/doc/src/filelib.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2003</year><year>2016</year> + <year>2003</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -60,6 +60,12 @@ <datatype> <name name="filename_all"/> </datatype> + <datatype> + <name name="find_file_rule"/> + </datatype> + <datatype> + <name name="find_source_rule"/> + </datatype> </datatypes> <funcs> @@ -226,7 +232,51 @@ filelib:wildcard("lib/**/*.{erl,hrl}")</code> directory.</p> </desc> </func> + + <func> + <name name="find_file" arity="2"/> + <name name="find_file" arity="3"/> + <fsummary>Find a file relative to a given directory.</fsummary> + <desc> + <p>Looks for a file of the given name by applying suffix rules to + the given directory path. For example, a rule <c>{"ebin", "src"}</c> + means that if the directory path ends with <c>"ebin"</c>, the + corresponding path ending in <c>"src"</c> should be searched.</p> + <p>If <c><anno>Rules</anno></c> is left out or is an empty list, the + default system rules are used. See also the Kernel application + parameter <seealso + marker="kernel:kernel_app#source_search_rules"><c>source_search_rules</c></seealso>.</p> + </desc> + </func> + <func> + <name name="find_source" arity="1"/> + <fsummary>Find the source file for a given object file.</fsummary> + <desc> + <p>Equivalent to <c>find_source(Base, Dir)</c>, where <c>Dir</c> is + <c>filename:dirname(<anno>FilePath</anno>)</c> and <c>Base</c> is + <c>filename:basename(<anno>FilePath</anno>)</c>.</p> + </desc> + </func> + <func> + <name name="find_source" arity="2"/> + <name name="find_source" arity="3"/> + <fsummary>Find a source file relative to a given directory.</fsummary> + <desc> + <p>Applies file extension specific rules to find the source file for + a given object file relative to the object directory. For example, + for a file with the extension <c>.beam</c>, the default rule is to + look for a file with a corresponding extension <c>.erl</c> by + replacing the suffix <c>"ebin"</c> of the object directory path with + <c>"src"</c>. + The file search is done through <seealso + marker="#find_file/3"><c>find_file/3</c></seealso>. The directory of + the object file is always tried before any other directory specified + by the rules.</p> + <p>If <c><anno>Rules</anno></c> is left out or is an empty list, the + default system rules are used. See also the Kernel application + parameter <seealso + marker="kernel:kernel_app#source_search_rules"><c>source_search_rules</c></seealso>.</p> + </desc> + </func> </funcs> </erlref> - - diff --git a/lib/stdlib/doc/src/filename.xml b/lib/stdlib/doc/src/filename.xml index 2a413835d0..14fd5ef787 100644 --- a/lib/stdlib/doc/src/filename.xml +++ b/lib/stdlib/doc/src/filename.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1997</year><year>2016</year> + <year>1997</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -356,10 +356,12 @@ true <p>Finds the source filename and compiler options for a module. The result can be fed to <seealso marker="compiler:compile#file/2"> <c>compile:file/2</c></seealso> to compile the file again.</p> - <warning><p>It is not recommended to use this function. If possible, - use the <seealso marker="beam_lib"><c>beam_lib(3)</c></seealso> - module to extract the abstract code format from the Beam file and - compile that instead.</p></warning> + <warning> + <p>This function is deprecated. Use <seealso marker="filelib#find_source/1"> + <c>filelib:find_source/1</c></seealso> instead for finding source files.</p> + <p>If possible, use the <seealso marker="beam_lib"><c>beam_lib(3)</c></seealso> + module to extract the compiler options and the abstract code + format from the Beam file and compile that instead.</p></warning> <p>Argument <c><anno>Beam</anno></c>, which can be a string or an atom, specifies either the module name or the path to the source code, with or without extension <c>".erl"</c>. In either @@ -511,6 +513,33 @@ true </func> <func> + <name name="safe_relative_path" arity="1"/> + <fsummary>Sanitize a relative path to avoid directory traversal attacks.</fsummary> + <desc> + <p>Sanitizes the relative path by eliminating ".." and "." + components to protect against directory traversal attacks. + Either returns the sanitized path name, or the atom + <c>unsafe</c> if the path is unsafe. + The path is considered unsafe in the following circumstances:</p> + <list type="bulleted"> + <item><p>The path is not relative.</p></item> + <item><p>A ".." component would climb up above the root of + the relative path.</p></item> + </list> + <p><em>Examples:</em></p> + <pre> +1> <input>filename:safe_relative_path("dir/sub_dir/..").</input> +"dir" +2> <input>filename:safe_relative_path("dir/..").</input> +[] +3> <input>filename:safe_relative_path("dir/../..").</input> +unsafe +4> <input>filename:safe_relative_path("/abs/path").</input> +unsafe</pre> + </desc> + </func> + + <func> <name name="split" arity="1"/> <fsummary>Split a filename into its path components.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/gb_sets.xml b/lib/stdlib/doc/src/gb_sets.xml index d677dd6f83..7bfe477a11 100644 --- a/lib/stdlib/doc/src/gb_sets.xml +++ b/lib/stdlib/doc/src/gb_sets.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2001</year><year>2015</year> + <year>2001</year><year>2016</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> diff --git a/lib/stdlib/doc/src/gb_trees.xml b/lib/stdlib/doc/src/gb_trees.xml index 9a49d66820..5cfff021c1 100644 --- a/lib/stdlib/doc/src/gb_trees.xml +++ b/lib/stdlib/doc/src/gb_trees.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2001</year><year>2015</year> + <year>2001</year><year>2016</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -109,6 +109,28 @@ </func> <func> + <name name="take" arity="2"/> + <fsummary>Returns a value and new tree without node with key <c>Key</c>.</fsummary> + <desc> + <p>Returns a value <c><anno>Value</anno></c> from node with key <c><anno>Key</anno></c> + and new <c><anno>Tree2</anno></c> without the node with this value. + Assumes that the node with key is present in the tree, + crashes otherwise.</p> + </desc> + </func> + + <func> + <name name="take_any" arity="2"/> + <fsummary>Returns a value and new tree without node with key <c>Key</c>.</fsummary> + <desc> + <p>Returns a value <c><anno>Value</anno></c> from node with key <c><anno>Key</anno></c> + and new <c><anno>Tree2</anno></c> without the node with this value. + Returns <c>error</c> if the node with the key is not present in + the tree.</p> + </desc> + </func> + + <func> <name name="empty" arity="0"/> <fsummary>Return an empty tree.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/gen_event.xml b/lib/stdlib/doc/src/gen_event.xml index c24542002a..012737c390 100644 --- a/lib/stdlib/doc/src/gen_event.xml +++ b/lib/stdlib/doc/src/gen_event.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -350,13 +350,18 @@ gen_event:stop -----> Module:terminate/2 <func> <name>start() -> Result</name> - <name>start(EventMgrName) -> Result</name> + <name>start(EventMgrName | Options) -> Result</name> + <name>start(EventMgrName, Options) -> Result</name> <fsummary>Create a stand-alone event manager process.</fsummary> <type> - <v>EventMgrName = {local,Name} | {global,GlobalName} - | {via,Module,ViaName}</v> + <v>EventMgrName = {local,Name} | {global,GlobalName} | {via,Module,ViaName}</v> <v> Name = atom()</v> <v> GlobalName = ViaName = term()</v> + <v>Options = [Option]</v> + <v> Option = {debug,Dbgs} | {timeout,Time} | {hibernate_after,HibernateAfterTimeout} | {spawn_opt,SOpts}</v> + <v> Dbgs = [Dbg]</v> + <v> Dbg = trace | log | statistics | {log_to_file,FileName} | {install,{Func,FuncState}}</v> + <v> SOpts = [term()]</v> <v>Result = {ok,Pid} | {error,{already_started,Pid}}</v> <v> Pid = pid()</v> </type> @@ -371,14 +376,19 @@ gen_event:stop -----> Module:terminate/2 <func> <name>start_link() -> Result</name> - <name>start_link(EventMgrName) -> Result</name> + <name>start_link(EventMgrName | Options) -> Result</name> + <name>start_link(EventMgrName, Options) -> Result</name> <fsummary>Create a generic event manager process in a supervision tree. </fsummary> <type> - <v>EventMgrName = {local,Name} | {global,GlobalName} - | {via,Module,ViaName}</v> + <v>EventMgrName = {local,Name} | {global,GlobalName} | {via,Module,ViaName}</v> <v> Name = atom()</v> <v> GlobalName = ViaName = term()</v> + <v>Options = [Option]</v> + <v> Option = {debug,Dbgs} | {timeout,Time} | {hibernate_after,HibernateAfterTimeout} | {spawn_opt,SOpts}</v> + <v> Dbgs = [Dbg]</v> + <v> Dbg = trace | log | statistics | {log_to_file,FileName} | {install,{Func,FuncState}}</v> + <v> SOpts = [term()]</v> <v>Result = {ok,Pid} | {error,{already_started,Pid}}</v> <v> Pid = pid()</v> </type> @@ -409,6 +419,12 @@ gen_event:stop -----> Module:terminate/2 <seealso marker="kernel:global"><c>global</c></seealso>. Thus, <c>{via,global,GlobalName}</c> is a valid reference.</p> </item> + <item> + <p>If option <c>{hibernate_after,HibernateAfterTimeout}</c> is present, the <c>gen_event</c> + process awaits any message for <c>HibernateAfterTimeout</c> milliseconds and + if no message is received, the process goes into hibernation automatically + (by calling <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso>).</p> + </item> </list> <p>If the event manager is successfully created, the function returns <c>{ok,Pid}</c>, where <c>Pid</c> is the pid of @@ -569,6 +585,13 @@ gen_event:stop -----> Module:terminate/2 <v>Extra = term()</v> </type> <desc> + <note> + <p>This callback is optional, so callback modules need not export it. + If a release upgrade/downgrade with <c>Change={advanced,Extra}</c> + specified in the <c>.appup</c> file is made when <c>code_change/3</c> + isn't implemented the event handler will crash with an <c>undef</c> error + reason.</p> + </note> <p>This function is called for an installed event handler that is to update its internal state during a release upgrade/downgrade, that is, when the instruction @@ -749,6 +772,12 @@ gen_event:stop -----> Module:terminate/2 <v> Id = term()</v> </type> <desc> + <note> + <p>This callback is optional, so callback modules need not + export it. The <c>gen_event</c> module provides a default + implementation of this function that logs about the unexpected + <c>Info</c> message, drops it and returns <c>{noreply, State}</c>.</p> + </note> <p>This function is called for each installed event handler when an event manager receives any other message than an event or a synchronous request (or a system message).</p> @@ -805,6 +834,11 @@ gen_event:stop -----> Module:terminate/2 <v> Args = Reason = Term = term()</v> </type> <desc> + <note> + <p>This callback is optional, so callback modules need not + export it. The <c>gen_event</c> module provides a default + implementation without cleanup.</p> + </note> <p>Whenever an event handler is deleted from an event manager, this function is called. It is to be the opposite of <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> diff --git a/lib/stdlib/doc/src/gen_fsm.xml b/lib/stdlib/doc/src/gen_fsm.xml index de06987d38..7187630b43 100644 --- a/lib/stdlib/doc/src/gen_fsm.xml +++ b/lib/stdlib/doc/src/gen_fsm.xml @@ -4,14 +4,14 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996-2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at - + http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software @@ -29,931 +29,176 @@ <rev></rev> </header> <module>gen_fsm</module> - <modulesummary>Generic finite state machine behavior.</modulesummary> - <description> - <note> - <p> - There is a new behaviour - <seealso marker="gen_statem"><c>gen_statem</c></seealso> - that is intended to replace <c>gen_fsm</c> for new code. - <c>gen_fsm</c> will not be removed for the foreseeable future - to keep old state machine implementations running. - </p> - </note> - <p>This behavior module provides a finite state machine. - A generic finite state machine process (<c>gen_fsm</c>) implemented - using this module has a standard set of interface functions - and includes functionality for tracing and error reporting. It - also fits into an OTP supervision tree. For more information, see - <seealso marker="doc/design_principles:fsm">OTP Design Principles</seealso>. - </p> - - <p>A <c>gen_fsm</c> process assumes all specific parts to be located in a - callback module exporting a predefined set of functions. The relationship - between the behavior functions and the callback functions is as - follows:</p> - - <pre> -gen_fsm module Callback module --------------- --------------- -gen_fsm:start -gen_fsm:start_link -----> Module:init/1 - -gen_fsm:stop -----> Module:terminate/3 - -gen_fsm:send_event -----> Module:StateName/2 - -gen_fsm:send_all_state_event -----> Module:handle_event/3 - -gen_fsm:sync_send_event -----> Module:StateName/3 - -gen_fsm:sync_send_all_state_event -----> Module:handle_sync_event/4 - -- -----> Module:handle_info/3 - -- -----> Module:terminate/3 + <modulesummary>Deprecated and replaced by gen_statem </modulesummary> -- -----> Module:code_change/4</pre> - - <p>If a callback function fails or returns a bad value, the <c>gen_fsm</c> - process terminates.</p> - - <p>A <c>gen_fsm</c> process handles system messages as described in - <seealso marker="sys"><c>sys(3)</c></seealso>. The <c>sys</c> module - can be used for debugging a <c>gen_fsm</c> process.</p> - - <p>Notice that a <c>gen_fsm</c> process does not trap exit signals - automatically, this must be explicitly initiated in the callback - module.</p> - - <p>Unless otherwise stated, all functions in this module fail if - the specified <c>gen_fsm</c> process does not exist or if bad arguments - are specified.</p> - - <p>The <c>gen_fsm</c> process can go into hibernation - (see <seealso marker="erts:erlang#hibernate/3"> - <c>erlang:hibernate/3</c></seealso>) if a callback function - specifies <c>'hibernate'</c> instead of a time-out value. This - can be useful if the server is expected to be idle for a long - time. However, use this feature with care, as hibernation - implies at least two garbage collections (when hibernating and - shortly after waking up) and is not something you want to do - between each call to a busy state machine.</p> + <description> + <p> Deprecated and replaced by <seealso marker="gen_statem"><c>gen_statem</c></seealso> </p> </description> - - <funcs> - <func> - <name>cancel_timer(Ref) -> RemainingTime | false</name> - <fsummary>Cancel an internal timer in a generic FSM.</fsummary> - <type> - <v>Ref = reference()</v> - <v>RemainingTime = integer()</v> - </type> - <desc> - <p>Cancels an internal timer referred by <c>Ref</c> in the - <c>gen_fsm</c> process that calls this function.</p> - <p><c>Ref</c> is a reference returned from - <seealso marker="#send_event_after/2"> - <c>send_event_after/2</c></seealso> or - <seealso marker="#start_timer/2"><c>start_timer/2</c></seealso>.</p> - <p>If the timer has already timed out, but the event not yet - been delivered, it is cancelled as if it had <em>not</em> - timed out, so there is no false timer event after - returning from this function.</p> - <p>Returns the remaining time in milliseconds until the timer would - have expired if <c>Ref</c> referred to an active timer, otherwise - <c>false</c>.</p> - </desc> - </func> - - <func> - <name>enter_loop(Module, Options, StateName, StateData)</name> - <name>enter_loop(Module, Options, StateName, StateData, FsmName)</name> - <name>enter_loop(Module, Options, StateName, StateData, Timeout)</name> - <name>enter_loop(Module, Options, StateName, StateData, FsmName, Timeout)</name> - <fsummary>Enter the <c>gen_fsm</c> receive loop.</fsummary> - <type> - <v>Module = atom()</v> - <v>Options = [Option]</v> - <v> Option = {debug,Dbgs}</v> - <v> Dbgs = [Dbg]</v> - <v> Dbg = trace | log | statistics</v> - <v> | {log_to_file,FileName} | {install,{Func,FuncState}}</v> - <v>StateName = atom()</v> - <v>StateData = term()</v> - <v>FsmName = {local,Name} | {global,GlobalName}</v> - <v> | {via,Module,ViaName}</v> - <v> Name = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Timeout = int() | infinity</v> - </type> - <desc> - <p>Makes an existing process into a <c>gen_fsm</c> process. - Does not return, - instead the calling process enters the <c>gen_fsm</c> receive - loop and becomes a <c>gen_fsm</c> process. The process <em>must</em> - have been started using one of the start functions in - <seealso marker="proc_lib"><c>proc_lib(3)</c></seealso>. The user is - responsible for any initialization of the process, including - registering a name for it.</p> - <p>This function is useful when a more complex initialization - procedure is needed than the <c>gen_fsm</c> behavior provides.</p> - <p><c>Module</c>, <c>Options</c>, and <c>FsmName</c> have - the same meanings as when calling - <seealso marker="#start_link/3"><c>start[_link]/3,4</c></seealso>. - However, if <c>FsmName</c> is specified, the process must have - been registered accordingly <em>before</em> this function is - called.</p> - <p><c>StateName</c>, <c>StateData</c>, and <c>Timeout</c> have - the same meanings as in the return value of - <seealso marker="#Moduleinit"><c>Module:init/1</c></seealso>. - The callback module <c>Module</c> does not need to - export an <c>init/1</c> function.</p> - <p>The function fails if the calling process was not started by a - <c>proc_lib</c> start function, or if it is not registered - according to <c>FsmName</c>.</p> - </desc> - </func> - - <func> - <name>reply(Caller, Reply) -> Result</name> - <fsummary>Send a reply to a caller.</fsummary> - <type> - <v>Caller - see below</v> - <v>Reply = term()</v> - <v>Result = term()</v> - </type> - <desc> - <p>This function can be used by a <c>gen_fsm</c> process to - explicitly send a reply to a client process that called - <seealso marker="#sync_send_event/2"> - <c>sync_send_event/2,3</c></seealso> or - <seealso marker="#sync_send_all_state_event/2"> - <c>sync_send_all_state_event/2,3</c></seealso> - when the reply cannot be defined in the return value of - <seealso marker="#Module:StateName/3"> - <c>Module:StateName/3</c></seealso> or - <seealso marker="#Module:handle_sync_event/4"> - <c>Module:handle_sync_event/4</c></seealso>.</p> - <p><c>Caller</c> must be the <c>From</c> argument provided to - the callback function. <c>Reply</c> is any term - given back to the client as the return value of - <c>sync_send_event/2,3</c> or - <c>sync_send_all_state_event/2,3</c>.</p> - <p>Return value <c>Result</c> is not further defined, and - is always to be ignored.</p> - </desc> - </func> - - <func> - <name>send_all_state_event(FsmRef, Event) -> ok</name> - <fsummary>Send an event asynchronously to a generic FSM.</fsummary> - <type> - <v>FsmRef = Name | {Name,Node} | {global,GlobalName}</v> - <v> | {via,Module,ViaName} | pid()</v> - <v> Name = Node = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Event = term()</v> - </type> - <desc> - <p>Sends an event asynchronously to the <c>FsmRef</c> of the - <c>gen_fsm</c> process and returns <c>ok</c> immediately. - The <c>gen_fsm</c> process calls - <seealso marker="#Module:handle_event/3"> - <c>Module:handle_event/3</c></seealso> to handle the event.</p> - <p>For a description of the arguments, see - <seealso marker="#send_event/2"><c>send_event/2</c></seealso>.</p> - <p>The difference between <c>send_event/2</c> and - <c>send_all_state_event/2</c> is which callback function is - used to handle the event. This function is useful when - sending events that are handled the same way in every state, - as only one <c>handle_event</c> clause is needed to handle - the event instead of one clause in each state name function.</p> - </desc> - </func> - - <func> - <name>send_event(FsmRef, Event) -> ok</name> - <fsummary>Send an event asynchronously to a generic FSM.</fsummary> - <type> - <v>FsmRef = Name | {Name,Node} | {global,GlobalName}</v> - <v> | {via,Module,ViaName} | pid()</v> - <v> Name = Node = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Event = term()</v> - </type> - <desc> - <p>Sends an event asynchronously to the <c>FsmRef</c> of the - <c>gen_fsm</c> process - and returns <c>ok</c> immediately. The <c>gen_fsm</c> process calls - <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso> to handle the event, where - <c>StateName</c> is the name of the current state of - the <c>gen_fsm</c> process.</p> - <p><c>FsmRef</c> can be any of the following:</p> - <list type="bulleted"> - <item>The pid</item> - <item><c>Name</c>, if the <c>gen_fsm</c> process is locally - registered</item> - <item><c>{Name,Node}</c>, if the <c>gen_fsm</c> process is locally - registered at another node</item> - <item><c>{global,GlobalName}</c>, if the <c>gen_fsm</c> process is - globally registered</item> - <item><c>{via,Module,ViaName}</c>, if the <c>gen_fsm</c> process is - registered through an alternative process registry</item> - </list> - <p><c>Event</c> is any term that is passed as one of - the arguments to <c>Module:StateName/2</c>.</p> - </desc> - </func> - - <func> - <name>send_event_after(Time, Event) -> Ref</name> - <fsummary>Send a delayed event internally in a generic FSM.</fsummary> - <type> - <v>Time = integer()</v> - <v>Event = term()</v> - <v>Ref = reference()</v> - </type> - <desc> - <p>Sends a delayed event internally in the <c>gen_fsm</c> process - that calls this function after <c>Time</c> milliseconds. - Returns immediately a - reference that can be used to cancel the delayed send using - <seealso marker="#cancel_timer/1"><c>cancel_timer/1</c></seealso>.</p> - <p>The <c>gen_fsm</c> process calls - <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso> to handle - the event, where <c>StateName</c> is the name of the current - state of the <c>gen_fsm</c> process at the time the delayed event is - delivered.</p> - <p><c>Event</c> is any term that is passed as one of - the arguments to <c>Module:StateName/2</c>.</p> - </desc> - </func> - - <func> - <name>start(Module, Args, Options) -> Result</name> - <name>start(FsmName, Module, Args, Options) -> Result</name> - <fsummary>Create a standalone <c>gen_fsm</c> process.</fsummary> - <type> - <v>FsmName = {local,Name} | {global,GlobalName}</v> - <v> | {via,Module,ViaName}</v> - <v> Name = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Module = atom()</v> - <v>Args = term()</v> - <v>Options = [Option]</v> - <v> Option = {debug,Dbgs} | {timeout,Time} | {spawn_opt,SOpts}</v> - <v> Dbgs = [Dbg]</v> - <v> Dbg = trace | log | statistics</v> - <v> | {log_to_file,FileName} | {install,{Func,FuncState}}</v> - <v> SOpts = [term()]</v> - <v>Result = {ok,Pid} | ignore | {error,Error}</v> - <v> Pid = pid()</v> - <v> Error = {already_started,Pid} | term()</v> - </type> - <desc> - <p>Creates a standalone <c>gen_fsm</c> process, that is, a process that - is not part of a supervision tree and thus has no supervisor.</p> - <p>For a description of arguments and return values, see - <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>.</p> - </desc> - </func> - - <func> - <name>start_link(Module, Args, Options) -> Result</name> - <name>start_link(FsmName, Module, Args, Options) -> Result</name> - <fsummary>Create a <c>gen_fsm</c> process in a supervision tree. - </fsummary> - <type> - <v>FsmName = {local,Name} | {global,GlobalName}</v> - <v> | {via,Module,ViaName}</v> - <v> Name = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Module = atom()</v> - <v>Args = term()</v> - <v>Options = [Option]</v> - <v> Option = {debug,Dbgs} | {timeout,Time} | {spawn_opt,SOpts}</v> - <v> Dbgs = [Dbg]</v> - <v> Dbg = trace | log | statistics</v> - <v> | {log_to_file,FileName} | {install,{Func,FuncState}}</v> - <v> SOpts = [SOpt]</v> - <v> SOpt - see erlang:spawn_opt/2,3,4,5</v> - <v>Result = {ok,Pid} | ignore | {error,Error}</v> - <v> Pid = pid()</v> - <v> Error = {already_started,Pid} | term()</v> - </type> - <desc> - <p>Creates a <c>gen_fsm</c> process as part of a supervision tree. - The function is to be called, directly or indirectly, by - the supervisor. For example, it ensures that - the <c>gen_fsm</c> process is linked to the supervisor.</p> - <p>The <c>gen_fsm</c> process calls - <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> to - initialize. To ensure a synchronized startup procedure, - <c>start_link/3,4</c> does not return until - <c>Module:init/1</c> has returned.</p> - <list type="bulleted"> - <item> - <p>If <c>FsmName={local,Name}</c>, the <c>gen_fsm</c> process is - registered locally as <c>Name</c> using <c>register/2</c>.</p> - </item> - <item> - <p>If <c>FsmName={global,GlobalName}</c>, the <c>gen_fsm</c> process - is registered globally as <c>GlobalName</c> using - <seealso marker="kernel:global#register_name/2"> - <c>global:register_name/2</c></seealso>.</p> - </item> - <item> - <p>If <c>FsmName={via,Module,ViaName}</c>, the <c>gen_fsm</c> - process registers with the registry represented by <c>Module</c>. - The <c>Module</c> callback is to export the functions - <c>register_name/2</c>, <c>unregister_name/1</c>, - <c>whereis_name/1</c>, and <c>send/2</c>, which are to behave - like the corresponding functions in - <seealso marker="kernel:global"><c>global</c></seealso>. - Thus, <c>{via,global,GlobalName}</c> is a valid reference.</p> - </item> - </list> - <p>If no name is provided, the <c>gen_fsm</c> process is not - registered.</p> - <p><c>Module</c> is the name of the callback module.</p> - <p><c>Args</c> is any term that is passed as - the argument to <c>Module:init/1</c>.</p> - <p>If option <c>{timeout,Time}</c> is present, the <c>gen_fsm</c> - process is allowed to spend <c>Time</c> milliseconds initializing - or it terminates and the start function returns - <c>{error,timeout}</c>.</p> - <p>If option <c>{debug,Dbgs}</c> is present, the corresponding - <c>sys</c> function is called for each item in <c>Dbgs</c>; see - <seealso marker="sys"><c>sys(3)</c></seealso>.</p> - <p>If option <c>{spawn_opt,SOpts}</c> is present, <c>SOpts</c> is - passed as option list to the <c>spawn_opt</c> BIF that is used to - spawn the <c>gen_fsm</c> process; see - <seealso marker="erts:erlang#spawn_opt/2"> - <c>spawn_opt/2</c></seealso>.</p> - <note> - <p>Using spawn option <c>monitor</c> is not - allowed, it causes the function to fail with reason - <c>badarg</c>.</p> - </note> - <p>If the <c>gen_fsm</c> process is successfully created and - initialized, the function returns <c>{ok,Pid}</c>, where <c>Pid</c> - is the pid of the <c>gen_fsm</c> process. If a process with the - specified <c>FsmName</c> exists already, the function returns - <c>{error,{already_started,Pid}}</c>, where <c>Pid</c> is - the pid of that process.</p> - <p>If <c>Module:init/1</c> fails with <c>Reason</c>, - the function returns <c>{error,Reason}</c>. If - <c>Module:init/1</c> returns <c>{stop,Reason}</c> or - <c>ignore</c>, the process is terminated and the function - returns <c>{error,Reason}</c> or <c>ignore</c>, respectively.</p> - </desc> - </func> - - <func> - <name>start_timer(Time, Msg) -> Ref</name> - <fsummary>Send a time-out event internally in a generic FSM.</fsummary> - <type> - <v>Time = integer()</v> - <v>Msg = term()</v> - <v>Ref = reference()</v> - </type> - <desc> - <p>Sends a time-out event internally in the <c>gen_fsm</c> - process that calls this function after <c>Time</c> milliseconds. - Returns immediately a - reference that can be used to cancel the timer using - <seealso marker="#cancel_timer/1"><c>cancel_timer/1</c></seealso>.</p> - <p>The <c>gen_fsm</c> process calls - <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso> to handle - the event, where <c>StateName</c> is the name of the current - state of the <c>gen_fsm</c> process at the time the time-out - message is delivered.</p> - <p><c>Msg</c> is any term that is passed in the - time-out message, <c>{timeout, Ref, Msg}</c>, as one of - the arguments to <c>Module:StateName/2</c>.</p> - </desc> - </func> - - <func> - <name>stop(FsmRef) -> ok</name> - <name>stop(FsmRef, Reason, Timeout) -> ok</name> - <fsummary>Synchronously stop a generic FSM.</fsummary> - <type> - <v>FsmRef = Name | {Name,Node} | {global,GlobalName}</v> - <v> | {via,Module,ViaName} | pid()</v> - <v> Node = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Reason = term()</v> - <v>Timeout = int()>0 | infinity</v> - </type> - <desc> - <p>Orders a generic finite state machine to exit with the specified - <c>Reason</c> and waits for it to terminate. The <c>gen_fsm</c> - process calls <seealso marker="#Module:terminate/3"> - <c>Module:terminate/3</c></seealso> before exiting.</p> - <p>The function returns <c>ok</c> if the generic finite state machine - terminates with the expected reason. Any other reason than - <c>normal</c>, <c>shutdown</c>, or <c>{shutdown,Term}</c> causes an - error report to be issued using - <seealso marker="kernel:error_logger#format/2"> - <c>error_logger:format/2</c></seealso>. - The default <c>Reason</c> is <c>normal</c>.</p> - <p><c>Timeout</c> is an integer greater than zero that - specifies how many milliseconds to wait for the generic FSM - to terminate, or the atom <c>infinity</c> to wait - indefinitely. The default value is <c>infinity</c>. If the - generic finite state machine has not terminated within the specified - time, a <c>timeout</c> exception is raised.</p> - <p>If the process does not exist, a <c>noproc</c> exception - is raised.</p> - </desc> - </func> - - <func> - <name>sync_send_all_state_event(FsmRef, Event) -> Reply</name> - <name>sync_send_all_state_event(FsmRef, Event, Timeout) -> Reply</name> - <fsummary>Send an event synchronously to a generic FSM.</fsummary> - <type> - <v>FsmRef = Name | {Name,Node} | {global,GlobalName}</v> - <v> | {via,Module,ViaName} | pid()</v> - <v> Name = Node = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Event = term()</v> - <v>Timeout = int()>0 | infinity</v> - <v>Reply = term()</v> - </type> - <desc> - <p>Sends an event to the <c>FsmRef</c> of the <c>gen_fsm</c> - process and waits until a reply arrives or a time-out occurs. - The <c>gen_fsm</c> process calls - <seealso marker="#Module:handle_sync_event/4"> - <c>Module:handle_sync_event/4</c></seealso> to handle the event.</p> - <p>For a description of <c>FsmRef</c> and <c>Event</c>, see - <seealso marker="#send_event/2">send_event/2</seealso>. - For a description of <c>Timeout</c> and <c>Reply</c>, see - <seealso marker="#sync_send_event/3"> - <c>sync_send_event/3</c></seealso>.</p> - <p>For a discussion about the difference between - <c>sync_send_event</c> and <c>sync_send_all_state_event</c>, see - <seealso marker="#send_all_state_event/2"> - <c>send_all_state_event/2</c></seealso>.</p> - </desc> - </func> - - <func> - <name>sync_send_event(FsmRef, Event) -> Reply</name> - <name>sync_send_event(FsmRef, Event, Timeout) -> Reply</name> - <fsummary>Send an event synchronously to a generic FSM.</fsummary> - <type> - <v>FsmRef = Name | {Name,Node} | {global,GlobalName}</v> - <v> | {via,Module,ViaName} | pid()</v> - <v> Name = Node = atom()</v> - <v> GlobalName = ViaName = term()</v> - <v>Event = term()</v> - <v>Timeout = int()>0 | infinity</v> - <v>Reply = term()</v> - </type> - <desc> - <p>Sends an event to the <c>FsmRef</c> of the <c>gen_fsm</c> - process and waits until a reply arrives or a time-out occurs. - <c>The gen_fsm</c> process calls - <seealso marker="#Module:StateName/3"> - <c>Module:StateName/3</c></seealso> to handle the event, where - <c>StateName</c> is the name of the current state of - the <c>gen_fsm</c> process.</p> - <p>For a description of <c>FsmRef</c> and <c>Event</c>, see - <seealso marker="#send_event/2"><c>send_event/2</c></seealso>.</p> - <p><c>Timeout</c> is an integer greater than zero that - specifies how many milliseconds to wait for a reply, or - the atom <c>infinity</c> to wait indefinitely. Defaults - to 5000. If no reply is received within the specified time, - the function call fails.</p> - <p>Return value <c>Reply</c> is defined in the return value - of <c>Module:StateName/3</c>.</p> - <note> - <p>The ancient behavior of sometimes consuming the server - exit message if the server died during the call while - linked to the client was removed in Erlang 5.6/OTP R12B.</p> - </note> - </desc> - </func> - </funcs> - - <section> - <title>Callback Functions</title> - <p>The following functions are to be exported from a <c>gen_fsm</c> - callback module.</p> - - <p><em>state name</em> denotes a state of the state machine.</p> - - <p><em>state data</em> denotes the internal state of the Erlang process - that implements the state machine.</p> - </section> - - <funcs> - <func> - <name>Module:code_change(OldVsn, StateName, StateData, Extra) -> {ok, NextStateName, NewStateData}</name> - <fsummary>Update the internal state data during upgrade/downgrade. - </fsummary> - <type> - <v>OldVsn = Vsn | {down, Vsn}</v> - <v> Vsn = term()</v> - <v>StateName = NextStateName = atom()</v> - <v>StateData = NewStateData = term()</v> - <v>Extra = term()</v> - </type> - <desc> - <p>This function is called by a <c>gen_fsm</c> process when it is to - update its internal state data during a release upgrade/downgrade, - that is, when instruction <c>{update,Module,Change,...}</c>, - where <c>Change={advanced,Extra}</c>, is given in - the <c>appup</c> file; see section - <seealso marker="doc/design_principles:release_handling#instr"> - Release Handling Instructions</seealso> in OTP Design Principles.</p> - <p>For an upgrade, <c>OldVsn</c> is <c>Vsn</c>, and for a downgrade, - <c>OldVsn</c> is <c>{down,Vsn}</c>. <c>Vsn</c> is defined by the - <c>vsn</c> attribute(s) of the old version of the callback module - <c>Module</c>. If no such attribute is defined, the version is - the checksum of the Beam file.</p> - <p><c>StateName</c> is the current state name and <c>StateData</c> the - internal state data of the <c>gen_fsm</c> process.</p> - <p><c>Extra</c> is passed "as is" from the <c>{advanced,Extra}</c> - part of the update instruction.</p> - <p>The function is to return the new current state name and - updated internal data.</p> - </desc> - </func> - - <func> - <name>Module:format_status(Opt, [PDict, StateData]) -> Status</name> - <fsummary>Optional function for providing a term describing the - current <c>gen_fsm</c> process status.</fsummary> - <type> - <v>Opt = normal | terminate</v> - <v>PDict = [{Key, Value}]</v> - <v>StateData = term()</v> - <v>Status = term()</v> - </type> - <desc> - <note> - <p>This callback is optional, so callback modules need not - export it. The <c>gen_fsm</c> module provides a default - implementation of this function that returns the callback - module state data.</p> - </note> - <p>This function is called by a <c>gen_fsm</c> process in the - following situations:</p> - <list type="bulleted"> - <item>One of <seealso marker="sys#get_status/1"> - <c>sys:get_status/1,2</c></seealso> - is invoked to get the <c>gen_fsm</c> status. <c>Opt</c> is set to - the atom <c>normal</c> for this case.</item> - <item>The <c>gen_fsm</c> process terminates abnormally and logs an - error. <c>Opt</c> is set to the atom <c>terminate</c> for - this case.</item> - </list> - <p>This function is useful for changing the form and - appearance of the <c>gen_fsm</c> status for these cases. A callback - module wishing to change the <c>sys:get_status/1,2</c> - return value as well as how its status appears in - termination error logs, exports an instance - of <c>format_status/2</c> that returns a term describing the - current status of the <c>gen_fsm</c> process.</p> - <p><c>PDict</c> is the current value of the process dictionary of the - <c>gen_fsm</c> process.</p> - <p><c>StateData</c> is the internal state data of the - <c>gen_fsm</c> process.</p> - <p>The function is to return <c>Status</c>, a term that - change the details of the current state and status of - the <c>gen_fsm</c> process. There are no restrictions on the - form <c>Status</c> can take, but for - the <c>sys:get_status/1,2</c> case (when <c>Opt</c> - is <c>normal</c>), the recommended form for - the <c>Status</c> value is <c>[{data, [{"StateData", - Term}]}]</c>, where <c>Term</c> provides relevant details of - the <c>gen_fsm</c> state data. Following this recommendation is not - required, but it makes the callback module status - consistent with the rest of the <c>sys:get_status/1,2</c> - return value.</p> - <p>One use for this function is to return compact alternative - state data representations to avoid that large state terms - are printed in log files.</p> - </desc> - </func> - - <func> - <name>Module:handle_event(Event, StateName, StateData) -> Result</name> - <fsummary>Handle an asynchronous event.</fsummary> - <type> - <v>Event = term()</v> - <v>StateName = atom()</v> - <v>StateData = term()</v> - <v>Result = {next_state,NextStateName,NewStateData}</v> - <v> | {next_state,NextStateName,NewStateData,Timeout}</v> - <v> | {next_state,NextStateName,NewStateData,hibernate}</v> - <v> | {stop,Reason,NewStateData}</v> - <v> NextStateName = atom()</v> - <v> NewStateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = term()</v> - </type> - <desc> - <p>Whenever a <c>gen_fsm</c> process receives an event sent using - <seealso marker="#send_all_state_event/2"> - <c>send_all_state_event/2</c></seealso>, - this function is called to handle the event.</p> - <p><c>StateName</c> is the current state name of the <c>gen_fsm</c> - process.</p> - <p>For a description of the other arguments and possible return values, - see <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso>.</p> - </desc> - </func> - - <func> - <name>Module:handle_info(Info, StateName, StateData) -> Result</name> - <fsummary>Handle an incoming message.</fsummary> - <type> - <v>Info = term()</v> - <v>StateName = atom()</v> - <v>StateData = term()</v> - <v>Result = {next_state,NextStateName,NewStateData}</v> - <v> | {next_state,NextStateName,NewStateData,Timeout}</v> - <v> | {next_state,NextStateName,NewStateData,hibernate}</v> - <v> | {stop,Reason,NewStateData}</v> - <v> NextStateName = atom()</v> - <v> NewStateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = normal | term()</v> - </type> - <desc> - <p>This function is called by a <c>gen_fsm</c> process when it receives - any other message than a synchronous or asynchronous event (or a - system message).</p> - <p><c>Info</c> is the received message.</p> - <p>For a description of the other arguments and possible return values, - see <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso>.</p> - </desc> - </func> - - <func> - <name>Module:handle_sync_event(Event, From, StateName, StateData) -> Result</name> - <fsummary>Handle a synchronous event.</fsummary> - <type> - <v>Event = term()</v> - <v>From = {pid(),Tag}</v> - <v>StateName = atom()</v> - <v>StateData = term()</v> - <v>Result = {reply,Reply,NextStateName,NewStateData}</v> - <v> | {reply,Reply,NextStateName,NewStateData,Timeout}</v> - <v> | {reply,Reply,NextStateName,NewStateData,hibernate}</v> - <v> | {next_state,NextStateName,NewStateData}</v> - <v> | {next_state,NextStateName,NewStateData,Timeout}</v> - <v> | {next_state,NextStateName,NewStateData,hibernate}</v> - <v> | {stop,Reason,Reply,NewStateData} | {stop,Reason,NewStateData}</v> - <v> Reply = term()</v> - <v> NextStateName = atom()</v> - <v> NewStateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = term()</v> - </type> - <desc> - <p>Whenever a <c>gen_fsm</c> process receives an event sent using - <seealso marker="#sync_send_all_state_event/2"> - <c>sync_send_all_state_event/2,3</c></seealso>, - this function is called to handle the event.</p> - <p><c>StateName</c> is the current state name of the <c>gen_fsm</c> - process.</p> - <p>For a description of the other arguments and possible return values, - see <seealso marker="#Module:StateName/3"> - <c>Module:StateName/3</c></seealso>.</p> - </desc> - </func> - - <func> - <name>Module:init(Args) -> Result</name> - <fsummary>Initialize process and internal state name and state data. - </fsummary> - <type> - <v>Args = term()</v> - <v>Result = {ok,StateName,StateData} | {ok,StateName,StateData,Timeout}</v> - <v> | {ok,StateName,StateData,hibernate}</v> - <v> | {stop,Reason} | ignore</v> - <v> StateName = atom()</v> - <v> StateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = term()</v> - </type> - <desc> - <marker id="Moduleinit"></marker> - <p>Whenever a <c>gen_fsm</c> process is started using - <seealso marker="#start/3"><c>start/3,4</c></seealso> or - <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>, - this function is called by the new process to initialize.</p> - <p><c>Args</c> is the <c>Args</c> argument provided to the start - function.</p> - <p>If initialization is successful, the function is to return - <c>{ok,StateName,StateData}</c>, - <c>{ok,StateName,StateData,Timeout}</c>, or - <c>{ok,StateName,StateData,hibernate}</c>, where <c>StateName</c> - is the initial state name and <c>StateData</c> the initial - state data of the <c>gen_fsm</c> process.</p> - <p>If an integer time-out value is provided, a time-out occurs - unless an event or a message is received within <c>Timeout</c> - milliseconds. A time-out is represented by the atom - <c>timeout</c> and is to be handled by the - <seealso marker="#Module:StateName/2"> - <c>Module:StateName/2</c></seealso> callback functions. The atom - <c>infinity</c> can be used to wait indefinitely, this is - the default value.</p> - <p>If <c>hibernate</c> is specified instead of a time-out value, the - process goes into hibernation when waiting for the next message - to arrive (by calling <seealso marker="proc_lib#hibernate/3"> - <c>proc_lib:hibernate/3</c></seealso>).</p> - <p>If the initialization fails, the function returns - <c>{stop,Reason}</c>, where <c>Reason</c> is any term, - or <c>ignore</c>.</p> - </desc> - </func> - - <func> - <name>Module:StateName(Event, StateData) -> Result</name> - <fsummary>Handle an asynchronous event.</fsummary> - <type> - <v>Event = timeout | term()</v> - <v>StateData = term()</v> - <v>Result = {next_state,NextStateName,NewStateData} </v> - <v> | {next_state,NextStateName,NewStateData,Timeout}</v> - <v> | {next_state,NextStateName,NewStateData,hibernate}</v> - <v> | {stop,Reason,NewStateData}</v> - <v> NextStateName = atom()</v> - <v> NewStateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = term()</v> - </type> - <desc> - <p>There is to be one instance of this function for each - possible state name. Whenever a <c>gen_fsm</c> process receives - an event sent using - <seealso marker="#send_event/2"><c>send_event/2</c></seealso>, - the instance of this function with the same name as - the current state name <c>StateName</c> is called to handle - the event. It is also called if a time-out occurs.</p> - <p><c>Event</c> is either the atom <c>timeout</c>, if a time-out - has occurred, or the <c>Event</c> argument provided to - <c>send_event/2</c>.</p> - <p><c>StateData</c> is the state data of the <c>gen_fsm</c> process.</p> - <p>If the function returns - <c>{next_state,NextStateName,NewStateData}</c>, - <c>{next_state,NextStateName,NewStateData,Timeout}</c>, or - <c>{next_state,NextStateName,NewStateData,hibernate}</c>, the - <c>gen_fsm</c> process continues executing with the current state - name set to <c>NextStateName</c> and with the possibly - updated state data <c>NewStateData</c>. For a description of - <c>Timeout</c> and <c>hibernate</c>, see - <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>.</p> - <p>If the function returns <c>{stop,Reason,NewStateData}</c>, - the <c>gen_fsm</c> process calls - <c>Module:terminate(Reason,StateName,NewStateData)</c> and - terminates.</p> - </desc> - </func> - - <func> - <name>Module:StateName(Event, From, StateData) -> Result</name> - <fsummary>Handle a synchronous event.</fsummary> - <type> - <v>Event = term()</v> - <v>From = {pid(),Tag}</v> - <v>StateData = term()</v> - <v>Result = {reply,Reply,NextStateName,NewStateData}</v> - <v> | {reply,Reply,NextStateName,NewStateData,Timeout}</v> - <v> | {reply,Reply,NextStateName,NewStateData,hibernate}</v> - <v> | {next_state,NextStateName,NewStateData}</v> - <v> | {next_state,NextStateName,NewStateData,Timeout}</v> - <v> | {next_state,NextStateName,NewStateData,hibernate}</v> - <v> | {stop,Reason,Reply,NewStateData} | {stop,Reason,NewStateData}</v> - <v> Reply = term()</v> - <v> NextStateName = atom()</v> - <v> NewStateData = term()</v> - <v> Timeout = int()>0 | infinity</v> - <v> Reason = normal | term()</v> - </type> - <desc> - <p>There is to be one instance of this function for each - possible state name. Whenever a <c>gen_fsm</c> process receives an - event sent using <seealso marker="#sync_send_event/2"> - <c>sync_send_event/2,3</c></seealso>, - the instance of this function with the same name as - the current state name <c>StateName</c> is called to handle - the event.</p> - <p><c>Event</c> is the <c>Event</c> argument provided to - <c>sync_send_event/2,3</c>.</p> - <p><c>From</c> is a tuple <c>{Pid,Tag}</c> where <c>Pid</c> is - the pid of the process that called <c>sync_send_event/2,3</c> - and <c>Tag</c> is a unique tag.</p> - <p><c>StateData</c> is the state data of the <c>gen_fsm</c> process.</p> - <list type="bulleted"> - <item> - <p>If <c>{reply,Reply,NextStateName,NewStateData}</c>, - <c>{reply,Reply,NextStateName,NewStateData,Timeout}</c>, or - <c>{reply,Reply,NextStateName,NewStateData,hibernate}</c> is - returned, <c>Reply</c> is given back to <c>From</c> as the return - value of <c>sync_send_event/2,3</c>. The <c>gen_fsm</c> process - then continues executing with the current state name set to - <c>NextStateName</c> and with the possibly updated state data - <c>NewStateData</c>. For a description of <c>Timeout</c> and - <c>hibernate</c>, see - <seealso marker="#Module:init/1"> - <c>Module:init/1</c></seealso>.</p> - </item> - <item> - <p>If <c>{next_state,NextStateName,NewStateData}</c>, - <c>{next_state,NextStateName,NewStateData,Timeout}</c>, or - <c>{next_state,NextStateName,NewStateData,hibernate}</c> is - returned, the <c>gen_fsm</c> process continues executing in - <c>NextStateName</c> with <c>NewStateData</c>. - Any reply to <c>From</c> must be specified explicitly using - <seealso marker="#reply/2"><c>reply/2</c></seealso>.</p> - </item> - <item> - <p>If the function returns - <c>{stop,Reason,Reply,NewStateData}</c>, <c>Reply</c> is - given back to <c>From</c>. If the function returns - <c>{stop,Reason,NewStateData}</c>, any reply to <c>From</c> - must be specified explicitly using <c>reply/2</c>. - The <c>gen_fsm</c> process then calls - <c>Module:terminate(Reason,StateName,NewStateData)</c> and - terminates.</p> - </item> - </list> - </desc> - </func> - - <func> - <name>Module:terminate(Reason, StateName, StateData)</name> - <fsummary>Clean up before termination.</fsummary> - <type> - <v>Reason = normal | shutdown | {shutdown,term()} | term()</v> - <v>StateName = atom()</v> - <v>StateData = term()</v> - </type> - <desc> - <p>This function is called by a <c>gen_fsm</c> process when it is about - to terminate. It is to be the opposite of - <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> - and do any necessary cleaning up. When it returns, the <c>gen_fsm</c> - process terminates with <c>Reason</c>. The return value is ignored. - </p> - <p><c>Reason</c> is a term denoting the stop reason, - <c>StateName</c> is the current state name, and - <c>StateData</c> is the state data of the <c>gen_fsm</c> process.</p> - <p><c>Reason</c> depends on why the <c>gen_fsm</c> process is - terminating. If - it is because another callback function has returned a stop - tuple <c>{stop,..}</c>, <c>Reason</c> has the value - specified in that tuple. If it is because of a failure, - <c>Reason</c> is the error reason.</p> - <p>If the <c>gen_fsm</c> process is part of a supervision tree and is - ordered by its supervisor to terminate, this function is called - with <c>Reason=shutdown</c> if the following conditions apply:</p> - <list type="bulleted"> - <item> - <p>The <c>gen_fsm</c> process has been set to trap exit signals.</p> - </item> - <item> - <p>The shutdown strategy as defined in the child specification of - the supervisor is an integer time-out value, not - <c>brutal_kill</c>.</p> - </item> - </list> - <p>Even if the <c>gen_fsm</c> process is <em>not</em> part of a - supervision tree, - this function is called if it receives an <c>'EXIT'</c> - message from its parent. <c>Reason</c> is the same as in - the <c>'EXIT'</c> message.</p> - <p>Otherwise, the <c>gen_fsm</c> process terminates immediately.</p> - <p>Notice that for any other reason than <c>normal</c>, - <c>shutdown</c>, or <c>{shutdown,Term}</c> the <c>gen_fsm</c> process - is assumed to terminate because of an error and an error report is - issued using <seealso marker="kernel:error_logger#format/2"> - <c>error_logger:format/2</c></seealso>.</p> - </desc> - </func> - </funcs> - <section> - <title>See Also</title> - <p><seealso marker="gen_event"><c>gen_event(3)</c></seealso>, - <seealso marker="gen_server"><c>gen_server(3)</c></seealso>, - <seealso marker="gen_statem"><c>gen_statem(3)</c></seealso>, - <seealso marker="proc_lib"><c>proc_lib(3)</c></seealso>, - <seealso marker="supervisor"><c>supervisor(3)</c></seealso>, - <seealso marker="sys"><c>sys(3)</c></seealso></p> + <marker id="Migration to gen_statem"/> + <title>Migration to gen_statem</title> + + <p>Here follows a simple example of turning a gen_fsm into + a <seealso marker="gen_statem"><c>gen_statem</c></seealso>. The example comes + from the previous Users Guide for <c>gen_fsm</c> </p> + + <code type="erl"> +-module(code_lock). +-define(NAME, code_lock). +%-define(BEFORE_REWRITE, true). + +-ifdef(BEFORE_REWRITE). +-behaviour(gen_fsm). +-else. +-behaviour(gen_statem). +-endif. + +-export([start_link/1, button/1, stop/0]). + +-ifdef(BEFORE_REWRITE). +-export([init/1, locked/2, open/2, handle_sync_event/4, handle_event/3, + handle_info/3, terminate/3, code_change/4]). +-else. +-export([init/1, callback_mode/0, locked/3, open/3, terminate/3, code_change/4]). +%% Add callback__mode/0 +%% Change arity of the state functions +%% Remove handle_info/3 +-endif. + +-ifdef(BEFORE_REWRITE). +start_link(Code) -> + gen_fsm:start_link({local, ?NAME}, ?MODULE, Code, []). +-else. +start_link(Code) -> + gen_statem:start_link({local,?NAME}, ?MODULE, Code, []). +-endif. + +-ifdef(BEFORE_REWRITE). +button(Digit) -> + gen_fsm:send_event(?NAME, {button, Digit}). +-else. +button(Digit) -> + gen_statem:cast(?NAME, {button,Digit}). + %% send_event is asynchronous and becomes a cast +-endif. + +-ifdef(BEFORE_REWRITE). +stop() -> + gen_fsm:sync_send_all_state_event(?NAME, stop). +-else. +stop() -> + gen_statem:call(?NAME, stop). + %% sync_send is synchronous and becomes call + %% all_state is handled by callback code in gen_statem +-endif. + +init(Code) -> + do_lock(), + Data = #{code => Code, remaining => Code}, + {ok, locked, Data}. + +-ifdef(BEFORE_REWRITE). +-else. +callback_mode() -> + state_functions. +%% state_functions mode is the mode most similar to +%% gen_fsm. There is also handle_event mode which is +%% a fairly different concept. +-endif. + +-ifdef(BEFORE_REWRITE). +locked({button, Digit}, Data0) -> + case analyze_lock(Digit, Data0) of + {open = StateName, Data} -> + {next_state, StateName, Data, 10000}; + {StateName, Data} -> + {next_state, StateName, Data} + end. +-else. +locked(cast, {button,Digit}, Data0) -> + case analyze_lock(Digit, Data0) of + {open = StateName, Data} -> + {next_state, StateName, Data, 10000}; + {StateName, Data} -> + {next_state, StateName, Data} + end; +locked({call, From}, Msg, Data) -> + handle_call(From, Msg, Data); +locked({info, Msg}, StateName, Data) -> + handle_info(Msg, StateName, Data). +%% Arity differs +%% All state events are dispatched to handle_call and handle_info help +%% functions. If you want to handle a call or cast event specifically +%% for this state you would add a special clause for it above. +-endif. + +-ifdef(BEFORE_REWRITE). +open(timeout, State) -> + do_lock(), + {next_state, locked, State}; +open({button,_}, Data) -> + {next_state, locked, Data}. +-else. +open(timeout, _, Data) -> + do_lock(), + {next_state, locked, Data}; +open(cast, {button,_}, Data) -> + {next_state, locked, Data}; +open({call, From}, Msg, Data) -> + handle_call(From, Msg, Data); +open(info, Msg, Data) -> + handle_info(Msg, open, Data). +%% Arity differs +%% All state events are dispatched to handle_call and handle_info help +%% functions. If you want to handle a call or cast event specifically +%% for this state you would add a special clause for it above. +-endif. + +-ifdef(BEFORE_REWRITE). +handle_sync_event(stop, _From, _StateName, Data) -> + {stop, normal, ok, Data}. + +handle_event(Event, StateName, Data) -> + {stop, {shutdown, {unexpected, Event, StateName}}, Data}. + +handle_info(Info, StateName, Data) -> + {stop, {shutdown, {unexpected, Info, StateName}}, StateName, Data}. +-else. +-endif. + +terminate(_Reason, State, _Data) -> + State =/= locked andalso do_lock(), + ok. +code_change(_Vsn, State, Data, _Extra) -> + {ok, State, Data}. + +%% Internal functions +-ifdef(BEFORE_REWRITE). +-else. +handle_call(From, stop, Data) -> + {stop_and_reply, normal, {reply, From, ok}, Data}. + +handle_info(Info, StateName, Data) -> + {stop, {shutdown, {unexpected, Info, StateName}}, StateName, Data}. +%% These are internal functions for handling all state events +%% and not behaviour callbacks as in gen_fsm +-endif. + +analyze_lock(Digit, #{code := Code, remaining := Remaining} = Data) -> + case Remaining of + [Digit] -> + do_unlock(), + {open, Data#{remaining := Code}}; + [Digit|Rest] -> % Incomplete + {locked, Data#{remaining := Rest}}; + _Wrong -> + {locked, Data#{remaining := Code}} + end. + +do_lock() -> + io:format("Lock~n", []). +do_unlock() -> + io:format("Unlock~n", []). + </code> </section> </erlref> diff --git a/lib/stdlib/doc/src/gen_server.xml b/lib/stdlib/doc/src/gen_server.xml index 4a7dd60858..7d137fc772 100644 --- a/lib/stdlib/doc/src/gen_server.xml +++ b/lib/stdlib/doc/src/gen_server.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -162,11 +162,6 @@ gen_server:abcast -----> Module:handle_cast/2 of <c>Module:handle_call/3</c>.</p> <p>The call can fail for many reasons, including time-out and the called <c>gen_server</c> process dying before or during the call.</p> - <note> - <p>The ancient behavior of sometimes consuming the server - exit message if the server died during the call while - linked to the client was removed in Erlang 5.6/OTP R12B.</p> - </note> </desc> </func> @@ -204,7 +199,7 @@ gen_server:abcast -----> Module:handle_cast/2 <type> <v>Module = atom()</v> <v>Options = [Option]</v> - <v> Option = {debug,Dbgs}</v> + <v> Option = {debug,Dbgs} | {hibernate_after,HibernateAfterTimeout}</v> <v> Dbgs = [Dbg]</v> <v> Dbg = trace | log | statistics</v> <v> | {log_to_file,FileName} | {install,{Func,FuncState}}</v> @@ -339,7 +334,7 @@ gen_server:abcast -----> Module:handle_cast/2 <v>Module = atom()</v> <v>Args = term()</v> <v>Options = [Option]</v> - <v> Option = {debug,Dbgs} | {timeout,Time} | {spawn_opt,SOpts}</v> + <v> Option = {debug,Dbgs} | {timeout,Time} | {hibernate_after,HibernateAfterTimeout} | {spawn_opt,SOpts}</v> <v> Dbgs = [Dbg]</v> <v> Dbg = trace | log | statistics | {log_to_file,FileName} | {install,{Func,FuncState}}</v> <v> SOpts = [term()]</v> @@ -369,7 +364,7 @@ gen_server:abcast -----> Module:handle_cast/2 <v>Module = atom()</v> <v>Args = term()</v> <v>Options = [Option]</v> - <v> Option = {debug,Dbgs} | {timeout,Time} | {spawn_opt,SOpts}</v> + <v> Option = {debug,Dbgs} | {timeout,Time} | {hibernate_after,HibernateAfterTimeout} | {spawn_opt,SOpts}</v> <v> Dbgs = [Dbg]</v> <v> Dbg = trace | log | statistics | {log_to_file,FileName} | {install,{Func,FuncState}}</v> <v> SOpts = [term()]</v> @@ -422,6 +417,12 @@ gen_server:abcast -----> Module:handle_cast/2 returns <c>{error,timeout}</c>.</p> </item> <item> + <p>If option <c>{hibernate_after,HibernateAfterTimeout}</c> is present, the <c>gen_server</c> + process awaits any message for <c>HibernateAfterTimeout</c> milliseconds and + if no message is received, the process goes into hibernation automatically + (by calling <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso>).</p> + </item> + <item> <p>If option <c>{debug,Dbgs}</c> is present, the corresponding <c>sys</c> function is called for each item in <c>Dbgs</c>; see @@ -509,6 +510,13 @@ gen_server:abcast -----> Module:handle_cast/2 <v>Reason = term()</v> </type> <desc> + <note> + <p>This callback is optional, so callback modules need not export it. + If a release upgrade/downgrade with <c>Change={advanced,Extra}</c> + specified in the <c>appup</c> file is made when <c>code_change/3</c> + isn't implemented the process will crash with an <c>undef</c> exit + reason.</p> + </note> <p>This function is called by a <c>gen_server</c> process when it is to update its internal state during a release upgrade/downgrade, that is, when the instruction <c>{update,Module,Change,...}</c>, @@ -695,6 +703,12 @@ gen_server:abcast -----> Module:handle_cast/2 <v> Reason = normal | term()</v> </type> <desc> + <note> + <p>This callback is optional, so callback modules need not + export it. The <c>gen_server</c> module provides a default + implementation of this function that logs about the unexpected + <c>Info</c> message, drops it and returns <c>{noreply, State}</c>.</p> + </note> <p>This function is called by a <c>gen_server</c> process when a time-out occurs or when it receives any other message than a synchronous or asynchronous request (or a system message).</p> @@ -755,6 +769,11 @@ gen_server:abcast -----> Module:handle_cast/2 <v>State = term()</v> </type> <desc> + <note> + <p>This callback is optional, so callback modules need not + export it. The <c>gen_server</c> module provides a default + implementation without cleanup.</p> + </note> <p>This function is called by a <c>gen_server</c> process when it is about to terminate. It is to be the opposite of <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> @@ -801,7 +820,6 @@ gen_server:abcast -----> Module:handle_cast/2 <section> <title>See Also</title> <p><seealso marker="gen_event"><c>gen_event(3)</c></seealso>, - <seealso marker="gen_fsm"><c>gen_fsm(3)</c></seealso>, <seealso marker="gen_statem"><c>gen_statem(3)</c></seealso>, <seealso marker="proc_lib"><c>proc_lib(3)</c></seealso>, <seealso marker="supervisor"><c>supervisor(3)</c></seealso>, diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index c57a31fa21..a7caa71dcb 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2016</year> + <year>2016</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -54,30 +54,37 @@ <p> This is a new behavior in Erlang/OTP 19.0. It has been thoroughly reviewed, is stable enough - to be used by at least two heavy OTP applications, and is here to stay. + to be used by at least two heavy OTP applications, + and is here to stay. Depending on user feedback, we do not expect but can find it necessary to make minor not backward compatible changes into Erlang/OTP 20.0. </p> </note> <p> - The <c>gen_statem</c> behavior is intended to replace - <seealso marker="gen_fsm"><c>gen_fsm</c></seealso> for new code. + The <c>gen_statem</c> behavior replaces + <seealso marker="gen_fsm"><c>gen_fsm</c> </seealso> in Erlang/OTP 20.0. It has the same features and adds some really useful: </p> <list type="bulleted"> - <item>State code is gathered.</item> - <item>The state can be any term.</item> - <item>Events can be postponed.</item> - <item>Events can be self-generated.</item> - <item>A reply can be sent from a later state.</item> - <item>There can be multiple <c>sys</c> traceable replies.</item> + <item>Gathered state code.</item> + <item>Arbitrary term state.</item> + <item>Event postponing.</item> + <item>Self-generated events.</item> + <item>State time-out.</item> + <item>Multiple generic named time-outs.</item> + <item>Absolute time-out time.</item> + <item>Automatic state enter calls.</item> + <item>Reply from other state than the request.</item> + <item>Multiple <c>sys</c> traceable replies.</item> </list> <p> The callback model(s) for <c>gen_statem</c> differs from the one for <seealso marker="gen_fsm"><c>gen_fsm</c></seealso>, - but it is still fairly easy to rewrite - from <c>gen_fsm</c> to <c>gen_statem</c>. + but it is still fairly easy to + <seealso marker="gen_fsm#Migration to gen_statem"> + rewrite from + </seealso> <c>gen_fsm</c> to <c>gen_statem</c>. </p> <p> A generic state machine process (<c>gen_statem</c>) implemented @@ -97,6 +104,9 @@ gen_statem module Callback module gen_statem:start gen_statem:start_link -----> Module:init/1 +Server start or code change + -----> Module:callback_mode/0 + gen_statem:stop -----> Module:terminate/3 gen_statem:call @@ -116,37 +126,40 @@ erlang:'!' -----> Module:StateName/3 </p> <p> If a callback function fails or returns a bad value, - the <c>gen_statem</c> terminates. However, an exception of class + the <c>gen_statem</c> terminates, unless otherwise stated. + However, an exception of class <seealso marker="erts:erlang#throw/1"><c>throw</c></seealso> - is not regarded as an error but as a valid return. + is not regarded as an error but as a valid return + from all callback functions. </p> - <marker id="state_function"/> + <marker id="state callback"/> <p> - The "<em>state function</em>" for a specific + The "<em>state callback</em>" for a specific <seealso marker="#type-state">state</seealso> in a <c>gen_statem</c> is the callback function that is called for all events in this state. It is selected depending on which <seealso marker="#type-callback_mode"><em>callback mode</em></seealso> - that the implementation specifies when the server starts. + that the callback module defines with the callback function + <seealso marker="#Module:callback_mode/0"><c>Module:callback_mode/0</c></seealso>. </p> <p> When the <seealso marker="#type-callback_mode"><em>callback mode</em></seealso> is <c>state_functions</c>, the state must be an atom and - is used as the state function name; see + is used as the state callback name; see <seealso marker="#Module:StateName/3"><c>Module:StateName/3</c></seealso>. This gathers all code for a specific state in one function as the <c>gen_statem</c> engine branches depending on state name. - Notice that in this mode the mandatory callback function + Note the fact that the callback function <seealso marker="#Module:terminate/3"><c>Module:terminate/3</c></seealso> - makes the state name <c>terminate</c> unusable. + makes the state name <c>terminate</c> unusable in this mode. </p> <p> When the <seealso marker="#type-callback_mode"><em>callback mode</em></seealso> is <c>handle_event_function</c>, the state can be any term - and the state function name is + and the state callback name is <seealso marker="#Module:handle_event/4"><c>Module:handle_event/4</c></seealso>. This makes it easy to branch depending on state or event as you desire. Be careful about which events you handle in which @@ -156,8 +169,8 @@ erlang:'!' -----> Module:StateName/3 <p> The <c>gen_statem</c> enqueues incoming events in order of arrival and presents these to the - <seealso marker="#state_function">state function</seealso> - in that order. The state function can postpone an event + <seealso marker="#state callback">state callback</seealso> + in that order. The state callback can postpone an event so it is not retried in the current state. After a state change the queue restarts with the postponed events. </p> @@ -169,12 +182,12 @@ erlang:'!' -----> Module:StateName/3 to entering a new receive statement. </p> <p> - The <seealso marker="#state_function">state function</seealso> + The <seealso marker="#state callback">state callback</seealso> can insert events using the <seealso marker="#type-action"><c>action()</c></seealso> <c>next_event</c> and such an event is inserted as the next to present - to the state function. That is, as if it is + to the state callback. That is, as if it is the oldest incoming event. A dedicated <seealso marker="#type-event_type"><c>event_type()</c></seealso> <c>internal</c> can be used for such events making them impossible @@ -187,9 +200,19 @@ erlang:'!' -----> Module:StateName/3 <seealso marker="gen_fsm"><c>gen_fsm</c></seealso> to force processing an inserted event before others. </p> + <p> + The <c>gen_statem</c> engine can automatically + make a specialized call to the + <seealso marker="#state callback">state callback</seealso> + whenever a new state is entered; see + <seealso marker="#type-state_enter"><c>state_enter()</c></seealso>. + This is for writing code common to all state entries. + Another way to do it is to insert events at state transitions, + but you have to do so everywhere it is needed. + </p> <note> <p>If you in <c>gen_statem</c>, for example, postpone - an event in one state and then call another state function + an event in one state and then call another state callback of yours, you have not changed states and hence the postponed event is not retried, which is logical but can be confusing. </p> @@ -218,7 +241,7 @@ erlang:'!' -----> Module:StateName/3 The <c>gen_statem</c> process can go into hibernation; see <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso>. It is done when a - <seealso marker="#state_function">state function</seealso> or + <seealso marker="#state callback">state callback</seealso> or <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> specifies <c>hibernate</c> in the returned <seealso marker="#type-action"><c>Actions</c></seealso> @@ -249,11 +272,10 @@ erlang:'!' -----> Module:StateName/3 -behaviour(gen_statem). -export([start/0,push/0,get_count/0,stop/0]). --export([terminate/3,code_change/4,init/1]). +-export([terminate/3,code_change/4,init/1,callback_mode/0]). -export([on/3,off/3]). name() -> pushbutton_statem. % The registered server name -callback_mode() -> state_functions. %% API. This example uses a registered name name() %% and does not link to the caller. @@ -270,15 +292,14 @@ stop() -> terminate(_Reason, _State, _Data) -> void. code_change(_Vsn, State, Data, _Extra) -> - {callback_mode(),State,Data}. + {ok,State,Data}. init([]) -> - %% Set the callback mode and initial state + data. - %% Data is used only as a counter. + %% Set the initial state + data. Data is used only as a counter. State = off, Data = 0, - {callback_mode(),State,Data}. - + {ok,State,Data}. +callback_mode() -> state_functions. -%%% State functions +%%% state callback(s) off({call,From}, push, Data) -> %% Go to 'on', increment count and reply @@ -325,19 +346,14 @@ ok <p> To compare styles, here follows the same example using <seealso marker="#type-callback_mode"><em>callback mode</em></seealso> - <c>state_functions</c>, or rather the code to replace - from function <c>init/1</c> of the <c>pushbutton.erl</c> + <c>handle_event_function</c>, or rather the code to replace + after function <c>init/1</c> of the <c>pushbutton.erl</c> example file above: </p> <code type="erl"> -init([]) -> - %% Set the callback mode and initial state + data. - %% Data is used only as a counter. - State = off, Data = 0, - {handle_event_function,State,Data}. - +callback_mode() -> handle_event_function. -%%% Event handling +%%% state callback(s) handle_event({call,From}, push, off, Data) -> %% Go to 'on', increment count and reply @@ -426,8 +442,8 @@ handle_event(_, _, State, Data) -> <desc> <p> Debug option that can be used when starting - a <c>gen_statem</c> server through, for example, - <seealso marker="#enter_loop/5"><c>enter_loop/5</c></seealso>. + a <c>gen_statem</c> server through, + <seealso marker="#enter_loop/4"><c>enter_loop/4-6</c></seealso>. </p> <p> For every entry in <c><anno>Dbgs</anno></c>, @@ -437,6 +453,21 @@ handle_event(_, _, State, Data) -> </desc> </datatype> <datatype> + <name name="hibernate_after_opt"/> + <desc> + <p> + hibernate_after option that can be used when starting + a <c>gen_statem</c> server through, + <seealso marker="#enter_loop/4"><c>enter_loop/4-6</c></seealso>. + </p> + <p>If option<seealso marker="#type-hibernate_after_opt"><c>{hibernate_after,HibernateAfterTimeout}</c></seealso> is present, the <c>gen_statem</c> + process awaits any message for <c>HibernateAfterTimeout</c> milliseconds and + if no message is received, the process goes into hibernation automatically + (by calling <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso>). + </p> + </desc> + </datatype> + <datatype> <name name="start_opt"/> <desc> <p> @@ -471,6 +502,10 @@ handle_event(_, _, State, Data) -> <name name="state"/> <desc> <p> + If the + <seealso marker="#type-callback_mode"><em>callback mode</em></seealso> + is <c>handle_event_function</c>, + the state can be any term. After a state change (<c>NextState =/= State</c>), all postponed events are retried. </p> @@ -484,6 +519,8 @@ handle_event(_, _, State, Data) -> <seealso marker="#type-callback_mode"><em>callback mode</em></seealso> is <c>state_functions</c>, the state must be of this type. + After a state change (<c>NextState =/= State</c>), + all postponed events are retried. </p> </desc> </datatype> @@ -514,9 +551,26 @@ handle_event(_, _, State, Data) -> originate from the corresponding API functions. For calls, the event contains whom to reply to. Type <c>info</c> originates from regular process messages sent - to the <c>gen_statem</c>. Also, the state machine - implementation can generate events of types - <c>timeout</c> and <c>internal</c> to itself. + to the <c>gen_statem</c>. The state machine + implementation can, in addition to the above, + generate + <seealso marker="#type-event_type"><c>events of types</c></seealso> + <c>timeout</c>, <c>{timeout,<anno>Name</anno>}</c>, + <c>state_timeout</c>, and <c>internal</c> to itself. + </p> + </desc> + </datatype> + <datatype> + <name name="callback_mode_result"/> + <desc> + <p> + This is the return type from + <seealso marker="#Module:callback_mode/0"><c>Module:callback_mode/0</c></seealso> + and selects + <seealso marker="#type-callback_mode">callback mode</seealso> + and whether to do + <seealso marker="#type-state_enter">state enter calls</seealso>, + or not. </p> </desc> </datatype> @@ -525,12 +579,9 @@ handle_event(_, _, State, Data) -> <desc> <p> The <em>callback mode</em> is selected when starting the - <c>gen_statem</c> using the return value from - <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> - or when calling - <seealso marker="#enter_loop/5"><c>enter_loop/5,6,7</c></seealso>, - and with the return value from - <seealso marker="#Module:code_change/4"><c>Module:code_change/4</c></seealso>. + <c>gen_statem</c> and after code change + using the return value from + <seealso marker="#Module:callback_mode/0"><c>Module:callback_mode/0</c></seealso>. </p> <taglist> <tag><c>state_functions</c></tag> @@ -555,16 +606,93 @@ handle_event(_, _, State, Data) -> </desc> </datatype> <datatype> + <name name="state_enter"/> + <desc> + <p> + Whether the state machine should use <em>state enter calls</em> + or not is selected when starting the <c>gen_statem</c> + and after code change using the return value from + <seealso marker="#Module:callback_mode/0"><c>Module:callback_mode/0</c></seealso>. + </p> + <p> + If + <seealso marker="#Module:callback_mode/0"><c>Module:callback_mode/0</c></seealso> + returns a list containing <c>state_enter</c>, + the <c>gen_statem</c> engine will, at every state change, + call the + <seealso marker="#state callback">state callback</seealso> + with arguments <c>(enter, OldState, Data)</c>. + This may look like an event but is really a call + performed after the previous state callback returned + and before any event is delivered to the new state callback. + See + <seealso marker="#Module:StateName/3"><c>Module:StateName/3</c></seealso> + and + <seealso marker="#Module:handle_event/4"><c>Module:handle_event/4</c></seealso>. + Such a call can be repeated by returning a + <seealso marker="#type-state_callback_result"> + <c>repeat_state</c> + </seealso> + or + <seealso marker="#type-state_callback_result"> + <c>repeat_state_and_data</c> + </seealso> + tuple from the state callback. + </p> + <p> + If + <seealso marker="#Module:callback_mode/0"><c>Module:callback_mode/0</c></seealso> + does not return such a list, no state enter calls are done. + </p> + <p> + If + <seealso marker="#Module:code_change/4"><c>Module:code_change/4</c></seealso> + should transform the state to a state with a different + name it is still regarded as the same state so this + does not cause a state enter call. + </p> + <p> + Note that a state enter call <em>will</em> be done + right before entering the initial state even though this + formally is not a state change. + In this case <c>OldState</c> will be the same as <c>State</c>, + which can not happen for a subsequent state change, + but will happen when repeating the state enter call. + </p> + </desc> + </datatype> + <datatype> <name name="transition_option"/> <desc> <p> Transition options can be set by <seealso marker="#type-action">actions</seealso> - and they modify the following in how - the state transition is done: + and they modify how the state transition is done: </p> <list type="ordered"> <item> + <p> + If the state changes, is the initial state, + <seealso marker="#type-state_callback_result"> + <c>repeat_state</c> + </seealso> + or + <seealso marker="#type-state_callback_result"> + <c>repeat_state_and_data</c> + </seealso> + is used, and also + <seealso marker="#type-state_enter"><em>state enter calls</em></seealso> + are used, the <c>gen_statem</c> calls + the new state callback with arguments + <seealso marker="#type-state_enter">(enter, OldState, Data)</seealso>. + Any + <seealso marker="#type-enter_action"><c>actions</c></seealso> + returned from this call are handled as if they were + appended to the actions + returned by the state callback that changed states. + </p> + </item> + <item> <p> All <seealso marker="#type-action">actions</seealso> @@ -590,27 +718,47 @@ handle_event(_, _, State, Data) -> All events stored with <seealso marker="#type-action"><c>action()</c></seealso> <c>next_event</c> - are inserted in the queue to be processed before - all other events. + are inserted to be processed before the other queued events. </p> </item> <item> <p> - If an + Time-out timers + <seealso marker="#type-event_timeout"><c>event_timeout()</c></seealso>, + <seealso marker="#type-generic_timeout"><c>generic_timeout()</c></seealso> + and + <seealso marker="#type-state_timeout"><c>state_timeout()</c></seealso> + are handled. Time-outs with zero time are guaranteed to be + delivered to the state machine before any external + not yet received event so if there is such a time-out requested, + the corresponding time-out zero event is enqueued as + the newest event. + </p> + <p> + Any event cancels an <seealso marker="#type-event_timeout"><c>event_timeout()</c></seealso> - is set through - <seealso marker="#type-action"><c>action()</c></seealso> - <c>timeout</c>, - an event timer can be started or a time-out zero event - can be enqueued. + so a zero time event time-out is only generated + if the event queue is empty. + </p> + <p> + A state change cancels a + <seealso marker="#type-state_timeout"><c>state_timeout()</c></seealso> + and any new transition option of this type + belongs to the new state. + </p> + </item> + <item> + <p> + If there are enqueued events the + <seealso marker="#state callback">state callback</seealso> + for the possibly new state + is called with the oldest enqueued event, + and we start again from the top of this list. </p> </item> <item> <p> - The (possibly new) - <seealso marker="#state_function">state function</seealso> - is called with the oldest enqueued event if there is any, - otherwise the <c>gen_statem</c> goes into <c>receive</c> + Otherwise the <c>gen_statem</c> goes into <c>receive</c> or hibernation (if <seealso marker="#type-hibernate"><c>hibernate()</c></seealso> @@ -618,8 +766,11 @@ handle_event(_, _, State, Data) -> to wait for the next message. In hibernation the next non-system event awakens the <c>gen_statem</c>, or rather the next incoming message awakens the <c>gen_statem</c>, - but if it is a system event - it goes right back into hibernation. + but if it is a system event it goes right back into hibernation. + When a new message arrives the + <seealso marker="#state callback">state callback</seealso> + is called with the corresponding event, + and we start again from the top of this list. </p> </item> </list> @@ -657,41 +808,140 @@ handle_event(_, _, State, Data) -> <name name="event_timeout"/> <desc> <p> - Generates an event of + Starts a timer set by + <seealso marker="#type-enter_action"><c>enter_action()</c></seealso> + <c>timeout</c>. + When the timer expires an event of <seealso marker="#type-event_type"><c>event_type()</c></seealso> - <c>timeout</c> - after this time (in milliseconds) unless another - event arrives in which case this time-out is cancelled. - Notice that a retried or inserted event - counts like a new in this respect. + <c>timeout</c> will be generated. + See + <seealso marker="erts:erlang#start_timer/4"><c>erlang:start_timer/4</c></seealso> + for how <c>Time</c> and + <seealso marker="#type-timeout_option"><c>Options</c></seealso> + are interpreted. Future <c>erlang:start_timer/4</c> <c>Options</c> + will not necessarily be supported. </p> <p> - If the value is <c>infinity</c>, no timer is started, as - it never triggers anyway. + Any event that arrives cancels this time-out. + Note that a retried or inserted event counts as arrived. + So does a state time-out zero event, if it was generated + before this time-out is requested. </p> <p> - If the value is <c>0</c>, the time-out event is immediately enqueued - unless there already are enqueued events, as the - time-out is then immediately cancelled. - This is a feature ensuring that a time-out <c>0</c> event - is processed before any not yet received external event. + If <c>Time</c> is <c>infinity</c>, + no timer is started, as it never would expire anyway. </p> <p> - Notice that it is not possible or needed to cancel this time-out, + If <c>Time</c> is relative and <c>0</c> + no timer is actually started, + instead the the time-out event is enqueued to ensure + that it gets processed before any not yet + received external event. + </p> + <p> + Note that it is not possible nor needed to cancel this time-out, as it is cancelled automatically by any other event. </p> </desc> </datatype> <datatype> + <name name="generic_timeout"/> + <desc> + <p> + Starts a timer set by + <seealso marker="#type-enter_action"><c>enter_action()</c></seealso> + <c>{timeout,Name}</c>. + When the timer expires an event of + <seealso marker="#type-event_type"><c>event_type()</c></seealso> + <c>{timeout,Name}</c> will be generated. + See + <seealso marker="erts:erlang#start_timer/4"><c>erlang:start_timer/4</c></seealso> + for how <c>Time</c> and + <seealso marker="#type-timeout_option"><c>Options</c></seealso> + are interpreted. Future <c>erlang:start_timer/4</c> <c>Options</c> + will not necessarily be supported. + </p> + <p> + If <c>Time</c> is <c>infinity</c>, + no timer is started, as it never would expire anyway. + </p> + <p> + If <c>Time</c> is relative and <c>0</c> + no timer is actually started, + instead the the time-out event is enqueued to ensure + that it gets processed before any not yet + received external event. + </p> + <p> + Setting a timer with the same <c>Name</c> while it is running + will restart it with the new time-out value. + Therefore it is possible to cancel + a specific time-out by setting it to <c>infinity</c>. + </p> + </desc> + </datatype> + <datatype> + <name name="state_timeout"/> + <desc> + <p> + Starts a timer set by + <seealso marker="#type-enter_action"><c>enter_action()</c></seealso> + <c>state_timeout</c>. + When the timer expires an event of + <seealso marker="#type-event_type"><c>event_type()</c></seealso> + <c>state_timeout</c> will be generated. + See + <seealso marker="erts:erlang#start_timer/4"><c>erlang:start_timer/4</c></seealso> + for how <c>Time</c> and + <seealso marker="#type-timeout_option"><c>Options</c></seealso> + are interpreted. Future <c>erlang:start_timer/4</c> <c>Options</c> + will not necessarily be supported. + </p> + <p> + If <c>Time</c> is <c>infinity</c>, + no timer is started, as it never would expire anyway. + </p> + <p> + If <c>Time</c> is relative and <c>0</c> + no timer is actually started, + instead the the time-out event is enqueued to ensure + that it gets processed before any not yet + received external event. + </p> + <p> + Setting this timer while it is running will restart it with + the new time-out value. Therefore it is possible to cancel + this time-out by setting it to <c>infinity</c>. + </p> + </desc> + </datatype> + <datatype> + <name name="timeout_option"/> + <desc> + <p> + If <c>Abs</c> is <c>true</c> an absolute timer is started, + and if it is <c>false</c> a relative, which is the default. + See + <seealso marker="erts:erlang#start_timer/4"><c>erlang:start_timer/4</c></seealso> + for details. + </p> + <p> + </p> + </desc> + </datatype> + <datatype> <name name="action"/> <desc> <p> These state transition actions can be invoked by returning them from the - <seealso marker="#state_function">state function</seealso>, from + <seealso marker="#state callback">state callback</seealso> + when it is called with an + <seealso marker="#type-event_type">event</seealso>, + from <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> or by giving them to - <seealso marker="#enter_loop/6"><c>enter_loop/6,7</c></seealso>. + <seealso marker="#enter_loop/5"><c>enter_loop/5,6</c></seealso>. </p> <p> Actions are executed in the containing list order. @@ -702,8 +952,8 @@ handle_event(_, _, State, Data) -> override any previous of the same type, so the last in the containing list wins. For example, the last - <seealso marker="#type-event_timeout"><c>event_timeout()</c></seealso> - overrides any other <c>event_timeout()</c> in the list. + <seealso marker="#type-postpone"><c>postpone()</c></seealso> + overrides any previous <c>postpone()</c> in the list. </p> <taglist> <tag><c>postpone</c></tag> @@ -720,6 +970,53 @@ handle_event(_, _, State, Data) -> as there is no event to postpone in those cases. </p> </item> + <tag><c>next_event</c></tag> + <item> + <p> + Stores the specified <c><anno>EventType</anno></c> + and <c><anno>EventContent</anno></c> for insertion after all + actions have been executed. + </p> + <p> + The stored events are inserted in the queue as the next to process + before any already queued events. The order of these stored events + is preserved, so the first <c>next_event</c> in the containing + list becomes the first to process. + </p> + <p> + An event of type + <seealso marker="#type-event_type"><c>internal</c></seealso> + is to be used when you want to reliably distinguish + an event inserted this way from any external event. + </p> + </item> + </taglist> + </desc> + </datatype> + <datatype> + <name name="enter_action"/> + <desc> + <p> + These state transition actions can be invoked by + returning them from the + <seealso marker="#state callback">state callback</seealso>, from + <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> + or by giving them to + <seealso marker="#enter_loop/5"><c>enter_loop/5,6</c></seealso>. + </p> + <p> + Actions are executed in the containing list order. + </p> + <p> + Actions that set + <seealso marker="#type-transition_option">transition options</seealso> + override any previous of the same type, + so the last in the containing list wins. + For example, the last + <seealso marker="#type-event_timeout"><c>event_timeout()</c></seealso> + overrides any previous <c>event_timeout()</c> in the list. + </p> + <taglist> <tag><c>hibernate</c></tag> <item> <p> @@ -735,10 +1032,9 @@ handle_event(_, _, State, Data) -> Short for <c>{timeout,Timeout,Timeout}</c>, that is, the time-out message is the time-out time. This form exists to make the - <seealso marker="#state_function">state function</seealso> + <seealso marker="#state callback">state callback</seealso> return value <c>{next_state,NextState,NewData,Timeout}</c> allowed like for <c>gen_fsm</c>'s - <seealso marker="gen_fsm#Module:StateName/2"><c>Module:StateName/2</c></seealso>. </p> </item> <tag><c>timeout</c></tag> @@ -747,33 +1043,32 @@ handle_event(_, _, State, Data) -> Sets the <seealso marker="#type-transition_option"><c>transition_option()</c></seealso> <seealso marker="#type-event_timeout"><c>event_timeout()</c></seealso> - to <c><anno>Time</anno></c> with <c><anno>EventContent</anno></c>. + to <c><anno>Time</anno></c> with <c><anno>EventContent</anno></c> + and time-out options + <seealso marker="#type-timeout_option"><c><anno>Options</anno></c></seealso>. </p> </item> - <tag><c>reply_action()</c></tag> + <tag><c>{timeout,<anno>Name</anno>}</c></tag> <item> <p> - Replies to a caller. + Sets the + <seealso marker="#type-transition_option"><c>transition_option()</c></seealso> + <seealso marker="#type-generic_timeout"><c>generic_timeout()</c></seealso> + to <c><anno>Time</anno></c> for <c><anno>Name</anno></c> + with <c><anno>EventContent</anno></c> + and time-out options + <seealso marker="#type-timeout_option"><c><anno>Options</anno></c></seealso>. </p> - </item> - <tag><c>next_event</c></tag> + </item> + <tag><c>state_timeout</c></tag> <item> <p> - Stores the specified <c><anno>EventType</anno></c> - and <c><anno>EventContent</anno></c> for insertion after all - actions have been executed. - </p> - <p> - The stored events are inserted in the queue as the next to process - before any already queued events. The order of these stored events - is preserved, so the first <c>next_event</c> in the containing - list becomes the first to process. - </p> - <p> - An event of type - <seealso marker="#type-event_type"><c>internal</c></seealso> - is to be used when you want to reliably distinguish - an event inserted this way from any external event. + Sets the + <seealso marker="#type-transition_option"><c>transition_option()</c></seealso> + <seealso marker="#type-state_timeout"><c>state_timeout()</c></seealso> + to <c><anno>Time</anno></c> with <c><anno>EventContent</anno></c> + and time-out options + <seealso marker="#type-timeout_option"><c><anno>Options</anno></c></seealso>. </p> </item> </taglist> @@ -783,39 +1078,97 @@ handle_event(_, _, State, Data) -> <name name="reply_action"/> <desc> <p> - Replies to a caller waiting for a reply in + This state transition action can be invoked by + returning it from the + <seealso marker="#state callback">state callback</seealso>, from + <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> + or by giving it to + <seealso marker="#enter_loop/5"><c>enter_loop/5,6</c></seealso>. + </p> + <p> + It replies to a caller waiting for a reply in <seealso marker="#call/2"><c>call/2</c></seealso>. <c><anno>From</anno></c> must be the term from argument <seealso marker="#type-event_type"><c>{call,<anno>From</anno>}</c></seealso> - to the - <seealso marker="#state_function">state function</seealso>. + in a call to a + <seealso marker="#state callback">state callback</seealso>. + </p> + <p> + Note that using this action from + <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> + or + <seealso marker="#enter_loop/5"><c>enter_loop/5,6</c></seealso> + would be weird on the border of witchcraft + since there has been no earlier call to a + <seealso marker="#state callback">state callback</seealso> + in this server. + </p> + </desc> + </datatype> + <datatype> + <name name="init_result"/> + <desc> + <p> + For a succesful initialization, + <c><anno>State</anno></c> is the initial + <seealso marker="#type-state"><c>state()</c></seealso> + and <c><anno>Data</anno></c> the initial server + <seealso marker="#type-data"><c>data()</c></seealso> + of the <c>gen_statem</c>. + </p> + <p> + The <seealso marker="#type-action"><c>Actions</c></seealso> + are executed when entering the first + <seealso marker="#type-state">state</seealso> just as for a + <seealso marker="#state callback">state callback</seealso>, + except that the action <c>postpone</c> is forced to + <c>false</c> since there is no event to postpone. + </p> + <p> + For an unsuccesful initialization, + <c>{stop,<anno>Reason</anno>}</c> + or <c>ignore</c> should be used; see + <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>. </p> </desc> </datatype> <datatype> - <name name="state_function_result"/> + <name name="state_enter_result"/> <desc> + <p> + <c><anno>State</anno></c> is the current state + and it can not be changed since the state callback + was called with a + <seealso marker="#type-state_enter"><em>state enter call</em></seealso>. + </p> <taglist> <tag><c>next_state</c></tag> <item> <p> The <c>gen_statem</c> does a state transition to - <c><anno>NextStateName</anno></c> - (which can be the same as the current state), + <c><anno>State</anno></c>, which has to be + the current state, sets <c><anno>NewData</anno></c>, and executes all <c><anno>Actions</anno></c>. </p> </item> </taglist> - <p> - All these terms are tuples or atoms and this property - will hold in any future version of <c>gen_statem</c>. - </p> </desc> </datatype> <datatype> - <name name="handle_event_result"/> + <name name="event_handler_result"/> <desc> + <p> + <c><anno>StateType</anno></c> is + <seealso marker="#type-state_name"><c>state_name()</c></seealso> + if + <seealso marker="#type-callback_mode"><em>callback mode</em></seealso> + is <c>state_functions</c>, or + <seealso marker="#type-state"><c>state()</c></seealso> + if + <seealso marker="#type-callback_mode"><em>callback mode</em></seealso> + is <c>handle_event_function</c>. + </p> <taglist> <tag><c>next_state</c></tag> <item> @@ -828,55 +1181,91 @@ handle_event(_, _, State, Data) -> </p> </item> </taglist> - <p> - All these terms are tuples or atoms and this property - will hold in any future version of <c>gen_statem</c>. - </p> </desc> </datatype> <datatype> - <name name="common_state_callback_result"/> + <name name="state_callback_result"/> <desc> + <p> + <c><anno>ActionType</anno></c> is + <seealso marker="#type-enter_action"><c>enter_action()</c></seealso> + if the state callback was called with a + <seealso marker="#type-state_enter"><em>state enter call</em></seealso> + and + <seealso marker="#type-action"><c>action()</c></seealso> + if the state callback was called with an event. + </p> <taglist> - <tag><c>stop</c></tag> + <tag><c>keep_state</c></tag> <item> <p> - Terminates the <c>gen_statem</c> by calling - <seealso marker="#Module:terminate/3"><c>Module:terminate/3</c></seealso> - with <c>Reason</c> and - <c><anno>NewData</anno></c>, if specified. + The <c>gen_statem</c> keeps the current state, or + does a state transition to the current state if you like, + sets <c><anno>NewData</anno></c>, + and executes all <c><anno>Actions</anno></c>. + This is the same as + <c>{next_state,CurrentState,<anno>NewData</anno>,<anno>Actions</anno>}</c>. </p> </item> - <tag><c>stop_and_reply</c></tag> + <tag><c>keep_state_and_data</c></tag> <item> <p> - Sends all <c><anno>Replies</anno></c>, - then terminates the <c>gen_statem</c> by calling - <seealso marker="#Module:terminate/3"><c>Module:terminate/3</c></seealso> - with <c>Reason</c> and - <c><anno>NewData</anno></c>, if specified. + The <c>gen_statem</c> keeps the current state or + does a state transition to the current state if you like, + keeps the current server data, + and executes all <c><anno>Actions</anno></c>. + This is the same as + <c>{next_state,CurrentState,CurrentData,<anno>Actions</anno>}</c>. </p> </item> - <tag><c>keep_state</c></tag> + <tag><c>repeat_state</c></tag> <item> <p> The <c>gen_statem</c> keeps the current state, or does a state transition to the current state if you like, sets <c><anno>NewData</anno></c>, and executes all <c><anno>Actions</anno></c>. - This is the same as - <c>{next_state,CurrentState,<anno>NewData</anno>,<anno>Actions</anno>}</c>. + If the <c>gen_statem</c> runs with + <seealso marker="#type-state_enter"><em>state enter calls</em></seealso>, + the state enter call is repeated, see type + <seealso marker="#type-transition_option"><c>transition_option()</c></seealso>, + otherwise <c>repeat_state</c> is the same as + <c>keep_state</c>. </p> </item> - <tag><c>keep_state_and_data</c></tag> + <tag><c>repeat_state_and_data</c></tag> <item> <p> - The <c>gen_statem</c> keeps the current state or + The <c>gen_statem</c> keeps the current state and data, or does a state transition to the current state if you like, - keeps the current server data, and executes all <c><anno>Actions</anno></c>. This is the same as - <c>{next_state,CurrentState,CurrentData,<anno>Actions</anno>}</c>. + <c>{repeat_state,CurrentData,<anno>Actions</anno>}</c>. + If the <c>gen_statem</c> runs with + <seealso marker="#type-state_enter"><em>state enter calls</em></seealso>, + the state enter call is repeated, see type + <seealso marker="#type-transition_option"><c>transition_option()</c></seealso>, + otherwise <c>repeat_state_and_data</c> is the same as + <c>keep_state_and_data</c>. + </p> + </item> + <tag><c>stop</c></tag> + <item> + <p> + Terminates the <c>gen_statem</c> by calling + <seealso marker="#Module:terminate/3"><c>Module:terminate/3</c></seealso> + with <c>Reason</c> and + <c><anno>NewData</anno></c>, if specified. + </p> + </item> + <tag><c>stop_and_reply</c></tag> + <item> + <p> + Sends all <c><anno>Replies</anno></c>, + then terminates the <c>gen_statem</c> by calling + <seealso marker="#Module:terminate/3"><c>Module:terminate/3</c></seealso> + with <c>Reason</c> and + <c><anno>NewData</anno></c>, if specified. </p> </item> </taglist> @@ -900,14 +1289,14 @@ handle_event(_, _, State, Data) -> by sending a request and waiting until its reply arrives. The <c>gen_statem</c> calls the - <seealso marker="#state_function">state function</seealso> with + <seealso marker="#state callback">state callback</seealso> with <seealso marker="#type-event_type"><c>event_type()</c></seealso> <c>{call,From}</c> and event content <c><anno>Request</anno></c>. </p> <p> A <c><anno>Reply</anno></c> is generated when a - <seealso marker="#state_function">state function</seealso> + <seealso marker="#state callback">state callback</seealso> returns with <c>{reply,From,<anno>Reply</anno>}</c> as one <seealso marker="#type-action"><c>action()</c></seealso>, @@ -923,17 +1312,40 @@ handle_event(_, _, State, Data) -> </p> <note> <p> - To avoid getting a late reply in the caller's - inbox, this function spawns a proxy process that + For <c><anno>Timeout</anno> < infinity</c>, + to avoid getting a late reply in the caller's + inbox if the caller should catch exceptions, + this function spawns a proxy process that does the call. A late reply gets delivered to the dead proxy process, hence gets discarded. This is less efficient than using - <c><anno>Timeout</anno> =:= infinity</c>. + <c><anno>Timeout</anno> == infinity</c>. + </p> + </note> + <p> + <c><anno>Timeout</anno></c> can also be a tuple + <c>{clean_timeout,<anno>T</anno>}</c> or + <c>{dirty_timeout,<anno>T</anno>}</c>, where + <c><anno>T</anno></c> is the time-out time. + <c>{clean_timeout,<anno>T</anno>}</c> works like + just <c>T</c> described in the note above + and uses a proxy process for <c>T < infinity</c>, + while <c>{dirty_timeout,<anno>T</anno>}</c> + bypasses the proxy process which is more lightweight. + </p> + <note> + <p> + If you combine catching exceptions from this function + with <c>{dirty_timeout,<anno>T</anno>}</c> + to avoid that the calling process dies when the call + times out, you will have to be prepared to handle + a late reply. + So why not just let the calling process die? </p> </note> <p> - The call can fail, for example, if the <c>gen_statem</c> dies - before or during this function call. + The call can also fail, for example, if the <c>gen_statem</c> + dies before or during this function call. </p> </desc> </func> @@ -949,7 +1361,7 @@ handle_event(_, _, State, Data) -> ignoring if the destination node or <c>gen_statem</c> does not exist. The <c>gen_statem</c> calls the - <seealso marker="#state_function">state function</seealso> with + <seealso marker="#state callback">state callback</seealso> with <seealso marker="#type-event_type"><c>event_type()</c></seealso> <c>cast</c> and event content <c><anno>Msg</anno></c>. @@ -958,35 +1370,36 @@ handle_event(_, _, State, Data) -> </func> <func> - <name name="enter_loop" arity="5"/> + <name name="enter_loop" arity="4"/> <fsummary>Enter the <c>gen_statem</c> receive loop.</fsummary> <desc> <p> The same as - <seealso marker="#enter_loop/7"><c>enter_loop/7</c></seealso> - except that no + <seealso marker="#enter_loop/6"><c>enter_loop/6</c></seealso> + with <c>Actions = []</c> except that no <seealso marker="#type-server_name"><c>server_name()</c></seealso> - must have been registered. + must have been registered. This creates an anonymous server. </p> </desc> </func> <func> - <name name="enter_loop" arity="6"/> + <name name="enter_loop" arity="5"/> <fsummary>Enter the <c>gen_statem</c> receive loop.</fsummary> <desc> <p> If <c><anno>Server_or_Actions</anno></c> is a <c>list()</c>, the same as - <seealso marker="#enter_loop/7"><c>enter_loop/7</c></seealso> + <seealso marker="#enter_loop/6"><c>enter_loop/6</c></seealso> except that no <seealso marker="#type-server_name"><c>server_name()</c></seealso> must have been registered and <c>Actions = <anno>Server_or_Actions</anno></c>. + This creates an anonymous server. </p> <p> Otherwise the same as - <seealso marker="#enter_loop/7"><c>enter_loop/7</c></seealso> + <seealso marker="#enter_loop/6"><c>enter_loop/6</c></seealso> with <c>Server = <anno>Server_or_Actions</anno></c> and <c>Actions = []</c>. @@ -995,7 +1408,7 @@ handle_event(_, _, State, Data) -> </func> <func> - <name name="enter_loop" arity="7"/> + <name name="enter_loop" arity="6"/> <fsummary>Enter the <c>gen_statem</c> receive loop.</fsummary> <desc> <p> @@ -1015,21 +1428,31 @@ handle_event(_, _, State, Data) -> the <c>gen_statem</c> behavior provides. </p> <p> - <c><anno>Module</anno></c>, <c><anno>Opts</anno></c>, and - <c><anno>Server</anno></c> have the same meanings - as when calling + <c><anno>Module</anno></c>, <c><anno>Opts</anno></c> + have the same meaning as when calling <seealso marker="#start_link/3"><c>start[_link]/3,4</c></seealso>. + </p> + <p> + If <c><anno>Server</anno></c> is <c>self()</c> an anonymous + server is created just as when using + <seealso marker="#start_link/3"><c>start[_link]/3</c></seealso>. + If <c><anno>Server</anno></c> is a + <seealso marker="#type-server_name"><c>server_name()</c></seealso> + a named server is created just as when using + <seealso marker="#start_link/4"><c>start[_link]/4</c></seealso>. However, the <seealso marker="#type-server_name"><c>server_name()</c></seealso> name must have been registered accordingly - <em>before</em> this function is called.</p> + <em>before</em> this function is called. + </p> <p> - <c><anno>CallbackMode</anno></c>, <c><anno>State</anno></c>, - <c><anno>Data</anno></c>, and <c><anno>Actions</anno></c> + <c><anno>State</anno></c>, <c><anno>Data</anno></c>, + and <c><anno>Actions</anno></c> have the same meanings as in the return value of <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso>. - Also, the callback module <c><anno>Module</anno></c> - does not need to export an <c>init/1</c> function. + Also, the callback module does not need to export a + <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> + function. </p> <p> The function fails if the calling process was not started by a @@ -1052,17 +1475,18 @@ handle_event(_, _, State, Data) -> <seealso marker="#call/2"><c>call/2</c></seealso> when the reply cannot be defined in the return value of a - <seealso marker="#state_function">state function</seealso>. + <seealso marker="#state callback">state callback</seealso>. </p> <p> <c><anno>From</anno></c> must be the term from argument <seealso marker="#type-event_type"><c>{call,<anno>From</anno>}</c></seealso> to the - <seealso marker="#state_function">state function</seealso>. - <c><anno>From</anno></c> and <c><anno>Reply</anno></c> - can also be specified using a - <seealso marker="#type-reply_action"><c>reply_action()</c></seealso> - and multiple replies with a list of them. + <seealso marker="#state callback">state callback</seealso>. + A reply or multiple replies canalso be sent + using one or several + <seealso marker="#type-reply_action"><c>reply_action()</c></seealso>s + from a + <seealso marker="#state callback">state callback</seealso>. </p> <note> <p> @@ -1142,6 +1566,13 @@ handle_event(_, _, State, Data) -> </p> </item> <item> + <p>If option<seealso marker="#type-hibernate_after_opt"><c>{hibernate_after,HibernateAfterTimeout}</c></seealso> is present, the <c>gen_statem</c> + process awaits any message for <c>HibernateAfterTimeout</c> milliseconds and + if no message is received, the process goes into hibernation automatically + (by calling <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso>). + </p> + </item> + <item> <p> If option <seealso marker="#type-debug_opt"><c>{debug,Dbgs}</c></seealso> @@ -1253,6 +1684,57 @@ handle_event(_, _, State, Data) -> <funcs> <func> + <name>Module:callback_mode() -> CallbackMode</name> + <fsummary>Update the internal state during upgrade/downgrade.</fsummary> + <type> + <v> + CallbackMode = + <seealso marker="#type-callback_mode">callback_mode()</seealso> | + [ <seealso marker="#type-callback_mode">callback_mode()</seealso> + | <seealso marker="#type-state_enter">state_enter()</seealso> ] + </v> + </type> + <desc> + <p> + This function is called by a <c>gen_statem</c> + when it needs to find out the + <seealso marker="#type-callback_mode"><em>callback mode</em></seealso> + of the callback module. The value is cached by <c>gen_statem</c> + for efficiency reasons, so this function is only called + once after server start and after code change, + but before the first + <seealso marker="#state callback">state callback</seealso> + in the current code version is called. + More occasions may be added in future versions + of <c>gen_statem</c>. + </p> + <p> + Server start happens either when + <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> + returns or when + <seealso marker="#enter_loop/4"><c>enter_loop/4-6</c></seealso> + is called. Code change happens when + <seealso marker="#Module:code_change/4"><c>Module:code_change/4</c></seealso> + returns. + </p> + <p> + The <c>CallbackMode</c> is either just + <seealso marker="#type-callback_mode"><c>callback_mode()</c></seealso> + or a list containing + <seealso marker="#type-callback_mode"><c>callback_mode()</c></seealso> + and possibly the atom + <seealso marker="#type-state_enter"><c>state_enter</c></seealso>. + </p> + <note> + <p> + If this function's body does not return an inline constant + value the callback module is doing something strange. + </p> + </note> + </desc> + </func> + + <func> <name>Module:code_change(OldVsn, OldState, OldData, Extra) -> Result </name> @@ -1262,11 +1744,7 @@ handle_event(_, _, State, Data) -> <v> Vsn = term()</v> <v>OldState = NewState = term()</v> <v>Extra = term()</v> - <v>Result = {NewCallbackMode,NewState,NewData} | Reason</v> - <v> - NewCallbackMode = - <seealso marker="#type-callback_mode">callback_mode()</seealso> - </v> + <v>Result = {ok,NewState,NewData} | Reason</v> <v> OldState = NewState = <seealso marker="#type-state">state()</seealso> @@ -1278,6 +1756,16 @@ handle_event(_, _, State, Data) -> <v>Reason = term()</v> </type> <desc> + <note> + <p> + This callback is optional, so callback modules need not export it. + If a release upgrade/downgrade with + <c>Change={advanced,Extra}</c> + specified in the <c>.appup</c> file is made + when <c>code_change/4</c> is not implemented + the process will crash with exit reason <c>undef</c>. + </p> + </note> <p> This function is called by a <c>gen_statem</c> when it is to update its internal state during a release upgrade/downgrade, @@ -1295,21 +1783,6 @@ handle_event(_, _, State, Data) -> <c>Module</c>. If no such attribute is defined, the version is the checksum of the Beam file. </p> - <note> - <p> - If you would dare to change - <seealso marker="#type-callback_mode"><em>callback mode</em></seealso> - during release upgrade/downgrade, the upgrade is no problem, - as the new code surely knows what <em>callback mode</em> - it needs. However, for a downgrade this function must - know from argument <c>Extra</c> that comes from the - <seealso marker="sasl:appup"><c>sasl:appup</c></seealso> - file what <em>callback mode</em> the old code did use. - It can also be possible to figure this out - from argument <c>{down,Vsn}</c>, as <c>Vsn</c> - in effect defines the old callback module version. - </p> - </note> <p> <c>OldState</c> and <c>OldData</c> is the internal state of the <c>gen_statem</c>. @@ -1321,41 +1794,46 @@ handle_event(_, _, State, Data) -> <p> If successful, the function must return the updated internal state in an - <c>{NewCallbackMode,NewState,NewData}</c> tuple. - </p> - <p> - If the function returns <c>Reason</c>, the ongoing - upgrade fails and rolls back to the old release.</p> - <p> - This function can use - <seealso marker="erts:erlang#throw/1"><c>erlang:throw/1</c></seealso> - to return <c>Result</c> or <c>Reason</c>. + <c>{ok,NewState,NewData}</c> tuple. + </p> + <p> + If the function returns a failure <c>Reason</c>, the ongoing + upgrade fails and rolls back to the old release. + Note that <c>Reason</c> can not be an <c>{ok,_,_}</c> tuple + since that will be regarded as a + <c>{ok,NewState,NewData}</c> tuple, + and that a tuple matching <c>{ok,_}</c> + is an also invalid failure <c>Reason</c>. + It is recommended to use an atom as <c>Reason</c> since + it will be wrapped in an <c>{error,Reason}</c> tuple. + </p> + <p> + Also note when upgrading a <c>gen_statem</c>, + this function and hence + the <c>Change={advanced,Extra}</c> parameter in the + <seealso marker="sasl:appup"><c>appup</c></seealso> file + is not only needed to update the internal state + or to act on the <c>Extra</c> argument. + It is also needed if an upgrade or downgrade should change + <seealso marker="#type-callback_mode"><em>callback mode</em></seealso>, + or else the callback mode after the code change + will not be honoured, + most probably causing a server crash. </p> </desc> </func> <func> - <name>Module:init(Args) -> Result</name> - <fsummary>Initialize process and internal state.</fsummary> + <name>Module:init(Args) -> Result(StateType)</name> + <fsummary> + Initializing process and internal state. + </fsummary> <type> <v>Args = term()</v> - <v>Result = {CallbackMode,State,Data}</v> - <v> | {CallbackMode,State,Data,Actions}</v> - <v> | {stop,Reason} | ignore</v> <v> - CallbackMode = - <seealso marker="#type-callback_mode">callback_mode()</seealso> + Result(StateType) = + <seealso marker="#type-init_result">init_result(StateType)</seealso> </v> - <v>State = <seealso marker="#type-state">state()</seealso></v> - <v> - Data = <seealso marker="#type-data">data()</seealso> - </v> - <v> - Actions = - [<seealso marker="#type-action">action()</seealso>] | - <seealso marker="#type-action">action()</seealso> - </v> - <v>Reason = term()</v> </type> <desc> <marker id="Module:init-1"/> @@ -1368,38 +1846,22 @@ handle_event(_, _, State, Data) -> the implementation state and server data. </p> <p> - <c>Args</c> is the <c>Args</c> argument provided to the start + <c>Args</c> is the <c>Args</c> argument provided to that start function. </p> - <p> - If the initialization is successful, the function is to - return <c>{CallbackMode,State,Data}</c> or - <c>{CallbackMode,State,Data,Actions}</c>. - <c>CallbackMode</c> selects the - <seealso marker="#type-callback_mode"><em>callback mode</em></seealso> - of the <c>gen_statem</c>. - <c>State</c> is the initial - <seealso marker="#type-state"><c>state()</c></seealso> - and <c>Data</c> the initial server - <seealso marker="#type-data"><c>data()</c></seealso>. - </p> - <p> - The <seealso marker="#type-action"><c>Actions</c></seealso> - are executed when entering the first - <seealso marker="#type-state">state</seealso> just as for a - <seealso marker="#state_function">state function</seealso>. - </p> - <p> - If the initialization fails, - the function is to return <c>{stop,Reason}</c> - or <c>ignore</c>; see - <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>. - </p> - <p> - This function can use - <seealso marker="erts:erlang#throw/1"><c>erlang:throw/1</c></seealso> - to return <c>Result</c>. - </p> + <note> + <p> + Note that if the <c>gen_statem</c> is started trough + <seealso marker="proc_lib"><c>proc_lib</c></seealso> + and + <seealso marker="#enter_loop/4"><c>enter_loop/4-6</c></seealso>, + this callback will never be called. + Since this callback is not optional it can + in that case be implemented as: + </p> + <pre> +init(Args) -> erlang:error(not_implemented, [Args]).</pre> + </note> </desc> </func> @@ -1430,10 +1892,14 @@ handle_event(_, _, State, Data) -> This callback is optional, so a callback module does not need to export it. The <c>gen_statem</c> module provides a default implementation of this function that returns - <c>{State,Data}</c>. If this callback fails, the default - function returns <c>{State,Info}</c>, - where <c>Info</c> informs of the crash but no details, - to hide possibly sensitive data. + <c>{State,Data}</c>. + </p> + <p> + If this callback is exported but fails, + to hide possibly sensitive data, + the default function will instead return <c>{State,Info}</c>, + where <c>Info</c> says nothing but the fact that + <c>format_status/2</c> has crashed. </p> </note> <p>This function is called by a <c>gen_statem</c> process when @@ -1474,7 +1940,8 @@ handle_event(_, _, State, Data) -> </p> <p> The function is to return <c>Status</c>, a term that - changes the details of the current state and status of + contains the appropriate details + of the current state and status of the <c>gen_statem</c>. There are no restrictions on the form <c>Status</c> can take, but for the <seealso marker="sys#get_status/1"><c>sys:get_status/1,2</c></seealso> @@ -1494,20 +1961,21 @@ handle_event(_, _, State, Data) -> printed in log files. Another use is to hide sensitive data from being written to the error log. </p> - <p> - This function can use - <seealso marker="erts:erlang#throw/1"><c>erlang:throw/1</c></seealso> - to return <c>Status</c>. - </p> </desc> </func> <func> + <name>Module:StateName(enter, OldState, Data) -> + StateEnterResult(StateName) + </name> <name>Module:StateName(EventType, EventContent, Data) -> StateFunctionResult </name> - <name>Module:handle_event(EventType, EventContent, - State, Data) -> HandleEventResult + <name>Module:handle_event(enter, OldState, State, Data) -> + StateEnterResult(State) + </name> + <name>Module:handle_event(EventType, EventContent, State, Data) -> + HandleEventResult </name> <fsummary>Handle an event.</fsummary> <type> @@ -1525,12 +1993,20 @@ handle_event(_, _, State, Data) -> <seealso marker="#type-data">data()</seealso> </v> <v> + StateEnterResult(StateName) = + <seealso marker="#type-state_enter_result">state_enter_result(StateName)</seealso> + </v> + <v> StateFunctionResult = - <seealso marker="#type-state_function_result">state_function_result()</seealso> + <seealso marker="#type-event_handler_result">event_handler_result</seealso>(<seealso marker="#type-state_name">state_name()</seealso>) + </v> + <v> + StateEnterResult(State) = + <seealso marker="#type-state_enter_result">state_enter_result(State)</seealso> </v> <v> HandleEventResult = - <seealso marker="#type-handle_event_result">handle_event_result()</seealso> + <seealso marker="#type-event_handler_result">event_handler_result</seealso>(<seealso marker="#type-state">state()</seealso>) </v> </type> <desc> @@ -1549,7 +2025,7 @@ handle_event(_, _, State, Data) -> <seealso marker="#type-event_type"><c>{call,From}</c></seealso>, the caller waits for a reply. The reply can be sent from this or from any other - <seealso marker="#state_function">state function</seealso> + <seealso marker="#state callback">state callback</seealso> by returning with <c>{reply,From,Reply}</c> in <seealso marker="#type-action"><c>Actions</c></seealso>, in <seealso marker="#type-reply_action"><c>Replies</c></seealso>, @@ -1573,9 +2049,41 @@ handle_event(_, _, State, Data) -> see <seealso marker="#type-action"><c>action()</c></seealso>. </p> <p> - These functions can use - <seealso marker="erts:erlang#throw/1"><c>erlang:throw/1</c></seealso>, - to return the result. + When the <c>gen_statem</c> runs with + <seealso marker="#type-state_enter">state enter calls</seealso>, + these functions are also called with arguments + <c>(enter, OldState, ...)</c> whenever the state changes. + In this case there are some restrictions on the + <seealso marker="#type-enter_action">actions</seealso> + that may be returned: + <seealso marker="#type-postpone"><c>postpone()</c></seealso> + is not allowed since a <em>state enter call</em> is not + an event so there is no event to postpone, and + <seealso marker="#type-action"><c>{next_event,_,_}</c></seealso> + is not allowed since using <em>state enter calls</em> + should not affect how events are consumed and produced. + You may also not change states from this call. + Should you return <c>{next_state,NextState, ...}</c> + with <c>NextState =/= State</c> the <c>gen_statem</c> crashes. + It is possible to use <c>{repeat_state, ...}</c>, + <c>{repeat_state_and_data,_}</c> or + <c>repeat_state_and_data</c> but all of them makes little + sense since you immediately will be called again with a new + <em>state enter call</em> making this just a weird way + of looping, and there are better ways to loop in Erlang. + You are advised to use <c>{keep_state,...}</c>, + <c>{keep_state_and_data,_}</c> or + <c>keep_state_and_data</c> since you can not change states + from a <em>state enter call</em> anyway. + </p> + <p> + Note the fact that you can use + <seealso marker="erts:erlang#throw/1"><c>throw</c></seealso> + to return the result, which can be useful. + For example to bail out with <c>throw(keep_state_and_data)</c> + from deep within complex code that can not + return <c>{next_state,State,Data}</c> because + <c>State</c> or <c>Data</c> is no longer in scope. </p> </desc> </func> @@ -1590,6 +2098,11 @@ handle_event(_, _, State, Data) -> <v>Ignored = term()</v> </type> <desc> + <note> + <p>This callback is optional, so callback modules need not + export it. The <c>gen_statem</c> module provides a default + implementation without cleanup.</p> + </note> <p> This function is called by a <c>gen_statem</c> when it is about to terminate. It is to be the opposite of @@ -1648,11 +2161,6 @@ handle_event(_, _, State, Data) -> and an error report is issued using <seealso marker="kernel:error_logger#format/2"><c>error_logger:format/2</c></seealso>. </p> - <p> - This function can use - <seealso marker="erts:erlang#throw/1"><c>erlang:throw/1</c></seealso> - to return <c>Ignored</c>, which is ignored anyway. - </p> </desc> </func> </funcs> diff --git a/lib/stdlib/doc/src/introduction.xml b/lib/stdlib/doc/src/introduction.xml index 5bf545c65f..642ca02430 100644 --- a/lib/stdlib/doc/src/introduction.xml +++ b/lib/stdlib/doc/src/introduction.xml @@ -5,7 +5,7 @@ <header> <copyright> <year>1999</year> - <year>2013</year> + <year>2016</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> diff --git a/lib/stdlib/doc/src/io.xml b/lib/stdlib/doc/src/io.xml index 11a64c7f8a..64fcf4379f 100644 --- a/lib/stdlib/doc/src/io.xml +++ b/lib/stdlib/doc/src/io.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -265,6 +265,8 @@ ok <p>Writes data with the standard syntax. This is used to output Erlang terms. Atoms are printed within quotes if they contain embedded non-printable characters. + Atom characters > 255 are escaped unless the + Unicode translation modifier (<c>t</c>) is used. Floats are printed accurately as the shortest, correctly rounded string.</p> </item> @@ -567,8 +569,6 @@ Prompt> <input><Characters beyond latin1 range not printable in this medium&g <item> <p>Similar to <c>s</c>, but the resulting string is converted into an atom.</p> - <p>The Unicode translation modifier is not allowed (atoms - cannot contain characters beyond the <c>latin1</c> range).</p> </item> <tag><c>c</c></tag> <item> diff --git a/lib/stdlib/doc/src/io_lib.xml b/lib/stdlib/doc/src/io_lib.xml index 931e50f6f2..bc1d77ac83 100644 --- a/lib/stdlib/doc/src/io_lib.xml +++ b/lib/stdlib/doc/src/io_lib.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -147,7 +147,7 @@ format string (that is, <c>~ts</c> or <c>~tc</c>), the resulting list can contain characters beyond the ISO Latin-1 character range (that is, numbers > 255). If so, the - result is not an ordinary Erlang <c>string()</c>, but can well be + result is still an ordinary Erlang <c>string()</c>, and can well be used in any context where Unicode data is allowed.</p> </desc> </func> @@ -356,7 +356,8 @@ <func> <name name="write" arity="1"/> - <name name="write" arity="2"/> + <name name="write" arity="2" clause_i="1"/> + <name name="write" arity="2" clause_i="2"/> <fsummary>Write a term.</fsummary> <desc> <p>Returns a character list that represents <c><anno>Term</anno></c>. @@ -384,6 +385,16 @@ </func> <func> + <name name="write_atom_as_latin1" arity="1"/> + <fsummary>Write an atom.</fsummary> + <desc> + <p>Returns the list of characters needed to print atom + <c><anno>Atom</anno></c>. Non-Latin-1 characters + are escaped.</p> + </desc> + </func> + + <func> <name name="write_char" arity="1"/> <fsummary>Write a character.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/maps.xml b/lib/stdlib/doc/src/maps.xml index e1edbadcd3..8c7270816b 100644 --- a/lib/stdlib/doc/src/maps.xml +++ b/lib/stdlib/doc/src/maps.xml @@ -160,7 +160,7 @@ val1 <p><em>Example:</em></p> <code type="none"> > Map = #{"42" => value}. -#{"42"> => value} +#{"42" => value} > maps:is_key("42",Map). true > maps:is_key(value,Map). diff --git a/lib/stdlib/doc/src/math.xml b/lib/stdlib/doc/src/math.xml index 1358ce5cbf..b4f096217a 100644 --- a/lib/stdlib/doc/src/math.xml +++ b/lib/stdlib/doc/src/math.xml @@ -57,9 +57,12 @@ <name name="atan" arity="1"/> <name name="atan2" arity="2"/> <name name="atanh" arity="1"/> + <name name="ceil" arity="1"/> <name name="cos" arity="1"/> <name name="cosh" arity="1"/> <name name="exp" arity="1"/> + <name name="floor" arity="1"/> + <name name="fmod" arity="2"/> <name name="log" arity="1"/> <name name="log10" arity="1"/> <name name="log2" arity="1"/> diff --git a/lib/stdlib/doc/src/notes.xml b/lib/stdlib/doc/src/notes.xml index ad2599c5a0..46454e9b80 100644 --- a/lib/stdlib/doc/src/notes.xml +++ b/lib/stdlib/doc/src/notes.xml @@ -4,7 +4,7 @@ <chapter> <header> <copyright> - <year>2004</year><year>2016</year> + <year>2004</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -31,6 +31,665 @@ </header> <p>This document describes the changes made to the STDLIB application.</p> +<section><title>STDLIB 3.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>For many releases, it has been legal to override a BIF + with a local function having the same name. However, + calling a local function with the same name as guard BIF + as filter in a list comprehension was not allowed.</p> + <p> + Own Id: OTP-13690</p> + </item> + <item> + <p> A new (default) pseudo-random number generator + algorithm Xoroshiro116+ has been implemented in the + <c>rand</c> module. </p><p> The old algorithm + implementations had a number of flaws so they are all + deprecated, but corrected versions of two of them have + been added. See the documentation. </p> + <p> + Own Id: OTP-14295 Aux Id: PR-1372 </p> + </item> + <item> + <p> The Erlang shell, <c>qlc:string_to_handle()</c>, and + the Debugger (the Evaluator area and Edit variable window + of the Bindings area) can parse pids, ports, references, + and external funs, as long as they can be created in the + running system. </p> + <p> + Own Id: OTP-14296</p> + </item> + <item> + <p>Internal code change: Calls to <c>catch</c> followed + by a call to <c>erlang:get_stacktrace/0</c> has been + rewritten to use <c>try</c> instead of <c>catch</c> to + make the code future-proof.</p> + <p> + Own Id: OTP-14400</p> + </item> + <item> + <p> The <c>ms_transform</c> module, used by + <c>ets:fun2ms/1</c> and <c>dbg:fun2ms/1</c>, evaluates + constant arithmetic expressions. This is necessary since + the Erlang compiler, which normally evaluates constant + expressions, does not recognize the format generated by + <c>ms_transform</c>. </p> + <p> + Own Id: OTP-14454 Aux Id: ERIERL-29 </p> + </item> + <item> + <p> The state machine engine <c>gen_statem</c> can now + handle generic time-outs (multiple named) as well as + absolute time-out time. See the documentation. </p><p> + The <c>gen_statem</c> callback <c>Module:init/1</c> has + become mandatory to harmonize with other <c>gen_*</c> + modules. This may be an incompatibility for + <c>gen_statem</c> callback modules that use + <c>gen_statem:enter_loop/4-6</c>. </p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14531</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + Improved unicode support for strings. Added normalization + functions in the <c>unicode</c> module. Extended the + <c>string</c> module API with new functions with improved + unicode handling and that works on grapheme clusters. The + new functions operates on the <c>unicode:chardata()</c> + type, thus they also accept <c>UTF-8 binaries</c> as + input. </p> + <p> + The old string API have been marked as obsolete. The + return values have been changed for some error cases.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-10289 Aux Id: OTP-10309 </p> + </item> + <item> + <p>There are two new guard BIFs '<c>floor/1</c>' and + '<c>ceil/1</c>'. They both return integers. In the + '<c>math</c>' module, there are two new BIFs with the + same names that return floating point values.</p> + <p> + Own Id: OTP-13692</p> + </item> + <item> + <p> + Making code_change, terminate and handle_info callbacks + optional in the OTP behaviours.</p> + <p> + Own Id: OTP-13801</p> + </item> + <item> + <p> The support for Dets files created with Erlang/OTP R7 + and earlier is removed. </p> + <p> + Own Id: OTP-13830</p> + </item> + <item> + <p>Replaced usage of deprecated symbolic <seealso + marker="erts:erlang#type-time_unit"><c>time + unit</c></seealso> representations.</p> + <p> + Own Id: OTP-13831 Aux Id: OTP-13735 </p> + </item> + <item> + <p>The function <c>fmod/2</c> has been added to the + <c>math</c> module.</p> + <p> + Own Id: OTP-14000</p> + </item> + <item> + <p>The EXIT signals received from processes using + <c>proc_lib</c> now looks like EXIT signals from + processes that were spawned using <c>spawn_link</c>. In + particular, that means that the stack trace is now + included in the EXIT signal so that it can see where the + process crashed.</p> + <p> + Own Id: OTP-14001</p> + </item> + <item> + <p><c>sets:add_element/2</c> is faster when adding an + element that is already present, and + <c>sets:del_element/2</c> is faster when the element to + be deleted is not present. This optimization can make + certain operations, such as sets:union/2 with many + overlapping elements, up to two orders of magnitude + faster.</p> + <p> + Own Id: OTP-14035</p> + </item> + <item> + <p> + Add information in doc about supervisor shutdown reason + when maximum restart frequency is reached.</p> + <p> + Own Id: OTP-14037 Aux Id: PR-1233 </p> + </item> + <item> + <p> + Added <c>rand:jump/[0|1]</c> functions.</p> + <p> + Own Id: OTP-14038 Aux Id: PR-1235 </p> + </item> + <item> + <p>Functions for detecting changed code has been added. + <c>code:modified_modules/0</c> returns all currently + loaded modules that have changed on disk. + <c>code:module_status/1</c> returns the status for a + module. In the shell and in <c>c</c> module, <c>mm/0</c> + is short for <c>code:modified_modules/0</c>, and + <c>lm/0</c> reloads all currently loaded modules that + have changed on disk.</p> + <p> + Own Id: OTP-14059</p> + </item> + <item> + <p>Each assert macro in <c>assert.hrl</c> now has a + corresponding version with an extra argument, for adding + comments to assertions. These can for example be printed + as part of error reports, to clarify the meaning of the + check that failed.</p> + <p> + Own Id: OTP-14066</p> + </item> + <item> + <p><c>error_logger_tty_h</c> and + <c>error_logger_file_h</c> now inserts the node + information for nonlocal messages before the message + itself instead of after, both for readability and so as + not to change the line termination property at the end of + the message.</p> + <p> + Own Id: OTP-14068</p> + </item> + <item> + <p>The Erlang code linter checks for badly formed type + constraints. </p> + <p> + Own Id: OTP-14070 Aux Id: PR-1214 </p> + </item> + <item> + <p>By default, there will now be a warning when + <c>export_all</c> is used. The warning can be disabled + using <c>nowarn_export_all</c>.</p> + <p> + Own Id: OTP-14071</p> + </item> + <item> + <p>When a <c>gen_server</c> process crashes, the + stacktrace for the client will be printed to facilitate + debugging.</p> + <p> + Own Id: OTP-14089</p> + </item> + <item> + <p>Optimized ETS operations by changing table identifier + type from integer to reference. The reference enables a + more direct mapping to the table with less potential lock + contention and makes especially creation and deletion of + tables scale much better.</p> <p>The change of the opaque + type for the ETS table identifiers may cause failure in + code that make faulty assumptions about this opaque + type.</p> <note> <p> The number of tables stored at one + Erlang node <em>used</em> to be limited. This is no + longer the case (except by memory usage). The previous + default limit was about 1400 tables and could be + increased by setting the environment variable + <c>ERL_MAX_ETS_TABLES</c> before starting the Erlang + runtime system. This hard limit has been removed, but it + is currently useful to set the <c>ERL_MAX_ETS_TABLES</c> + anyway. It should be set to an approximate of the maximum + amount of tables used. This since an internal table for + named tables is sized using this value. If large amounts + of named tables are used and <c>ERL_MAX_ETS_TABLES</c> + hasn't been increased, the performance of named table + lookup will degrade. </p> </note> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14094</p> + </item> + <item> + <p><c>take/2</c> has been added to <c>dict</c>, + <c>orddict</c>, and <c>gb_trees</c>. <c>take_any/2</c> + has been added to <c>gb_trees</c>.</p> + <p> + Own Id: OTP-14102</p> + </item> + <item> + <p> + Extend gen_event API to handle options as well.</p> + <p> + Own Id: OTP-14123</p> + </item> + <item> + <p> + Advice on how to tune the supervisor restart frequency + (intensity and period) is added to System Documentation - + Design Principles - Supervisor Behaviour.</p> + <p> + Own Id: OTP-14168 Aux Id: PR-1289 </p> + </item> + <item> + <p> + gen_fsm is deprecated and is replaced by gen_statem, + however for backwards compatibility reasons gen_fsm may + continue to exist as an undocumented feature for quite + some time.</p> + <p> + Own Id: OTP-14183</p> + </item> + <item> + <p>The shell functions <c>c/1</c> and <c>c/2</c> have + been extended so that if the argument is a module name + instead of a file name, it automatically locates the + .beam file and the corresponding source file, and then + recompiles the module using the same compiler options + (plus any options passed to c/2). If compilation fails, + the old beam file is preserved. Also adds <c>c(Mod, Opts, + Filter)</c>, where the Filter argument allows you to + remove old compiler options before the new options are + added.</p> <p>New utility functions <c>file_find/2/3</c> + and <c>find_source/1/2/3</c> have been added to + <c>filelib</c>.</p> + <p> + Own Id: OTP-14190</p> + </item> + <item> + <p><c>erl_tar</c> in previous versions of OTP only + supports the USTAR format. That limited path names to at + most 255 bytes, and did not support Unicode characters in + names in a portable way.</p> + <p><c>erl_tar</c> now has support for reading tar + archives in the formats currently in common use, such as + v7, STAR, USTAR, PAX, and GNU tar's extensions to the + STAR/USTAR format. When writing tar archives, + <c>erl_tar</c> can now write them in the <c>PAX</c> + format if necessary (for example, to support very long + filenames or filenames with Unicode characters). If + possible, <c>erl_tar</c> will still write tar archives in + the USTAR for maximum portability.</p> + <p> + Own Id: OTP-14226</p> + </item> + <item> + <p><c>base64:mime_decode/1</c> has been optimized so that + it is now almost as fast as<c>base64:decode/1</c>; it + used be noticeably slower.</p> + <p> + Own Id: OTP-14245</p> + </item> + <item> + <p><c>erl_tar</c> will now strip any leading '<c>/</c>' + from pathnames when extracting files from a tar archive + and write a message to the error logger. There is also + new check for directory traversal attacks; if a relative + path points above the current working directory the + extraction will be aborted.</p> + <p> + Own Id: OTP-14278</p> + </item> + <item> + <p> Miscellaneous updates due to atoms containing + arbitrary Unicode characters. </p> + <p> + Own Id: OTP-14285</p> + </item> + <item> + <p> + The Crypto application now supports generation of + cryptographically strong random numbers (floats < 1.0 + and integer arbitrary ranges) as a plugin to the 'rand' + module.</p> + <p> + Own Id: OTP-14317 Aux Id: PR-1372 </p> + </item> + <item> + <p> + Add new function <c>ets:select_replace/2</c> which + performs atomic "compare-and-swap" operations for ETS + objects using match specifications.</p> + <p> + Own Id: OTP-14319 Aux Id: PR-1076 </p> + </item> + <item> + <p> The Erlang code linter checks for bad <c>dialyzer</c> + attributes. It also checks for bad type variables in type + declarations. </p> + <p> + Own Id: OTP-14323</p> + </item> + <item> + <p> Two new functions has been implemented in the + <c>rand</c> module; <c>normal/2</c> and + <c>normal_s/3</c>, that both produce normal distribution + (pseudo) random numbers with mean value and variance + according to arguments. </p> + <p> + Own Id: OTP-14328 Aux Id: PR-1382 </p> + </item> + <item> + <p> + Upgraded the OTP internal PCRE library from version 8.33 + to version 8.40. This library is used for implementation + of the <seealso marker="stdlib:re"><c>re</c></seealso> + regular expressions module.</p> + <p> + Besides various bug fixes, the new version allows for + better stack protection. In order to utilize this + feature, the stack size of normal scheduler threads is + now by default set to 128 kilo words on all platforms. + The stack size of normal scheduler threads can be set + upon system start by passing the <seealso + marker="erts:erl#sched_thread_stack_size"><c>+sss</c></seealso> + command line argument to the <seealso + marker="erts:erl"><c>erl</c></seealso> command.</p> + <p> + See <url + href="http://pcre.org/original/changelog.txt"><c>http://pcre.org/original/changelog.txt</c></url> + for information about changes made to PCRE between the + versions 8.33 and 8.40.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14331 Aux Id: ERL-208 </p> + </item> + <item> + <p> + Added function <c>re:version/0</c> which returns + information about the OTP internal PCRE version used for + implementation of the <c>re</c> module.</p> + <p> + Own Id: OTP-14347 Aux Id: PR-1412 </p> + </item> + <item> + <p>The format of debug information that is stored in BEAM + files (when <c>debug_info</c> is used) has been changed. + The purpose of the change is to better support other + BEAM-based languages such as Elixir or LFE.</p> + <p>All tools included in OTP (dialyzer, debugger, cover, + and so on) will handle both the new format and the + previous format. Tools that retrieve the debug + information using <c>beam_lib:chunk(Beam, + [abstract_code])</c> will continue to work with both the + new and old format. Tools that call + <c>beam_lib:chunk(Beam, ["Abst"])</c> will not work with + the new format.</p> + <p>For more information, see the description of + <c>debug_info</c> in the documentation for + <c>beam_lib</c> and the description of the + <c>{debug_info,{Backend,Data}}</c> option in the + documentation for <c>compile</c>.</p> + <p> + Own Id: OTP-14369 Aux Id: PR-1367 </p> + </item> + <item> + <p> + Add option hibernate_after to gen_server, gen_statem and + gen_event. Also added to the deprecated gen_fsm + behaviour.</p> + <p> + Own Id: OTP-14405</p> + </item> + <item> + <p> The size of crash reports created by + <c>gen_server</c>, <c>gen_statem</c> and <c>proc_lib</c> + is limited with aid of the Kernel application variable + <c>error_logger_format_depth</c>. The purpose is to limit + the size of the messages sent to the <c>error_logger</c> + process when processes with huge message queues or states + crash. </p> <p>The crash report generated by + <c>proc_lib</c> includes the new tag + <c>message_queue_len</c>. The neighbour report also + includes the new tag <c>current_stacktrace</c>. Finally, + the neighbour report no longer includes the tags + <c>messages</c> and <c>dictionary</c>. </p> <p> The new + function <c>error_logger:get_format_depth/0</c> can be + used to retrieve the value of the Kernel application + variable <c>error_logger_format_depth</c>. </p> + <p> + Own Id: OTP-14417</p> + </item> + </list> + </section> + +</section> + +<section><title>STDLIB 3.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>An escript with only two lines would not work.</p> + <p> + Own Id: OTP-14098</p> + </item> + <item> + <p> Characters (<c>$char</c>) can be used in constant + pattern expressions. They can also be used in types and + contracts. </p> + <p> + Own Id: OTP-14103 Aux Id: ERL-313 </p> + </item> + <item> + <p> The signatures of <c>erl_parse:anno_to_term/1</c> and + <c>erl_parse:anno_from_term/1</c> are corrected. Using + these functions no longer results in false Dialyzer + warnings. </p> + <p> + Own Id: OTP-14131</p> + </item> + <item> + <p>Pretty-printing of maps is improved. </p> + <p> + Own Id: OTP-14175 Aux Id: seq13277 </p> + </item> + <item> + <p>If any of the following functions in the <c>zip</c> + module crashed, a file would be left open: + <c>extract()</c>, <c>unzip()</c>, <c>create()</c>, or + <c>zip()</c>. This has been corrected.</p> + <p>A <c>zip</c> file having a "Unix header" could not be + unpacked.</p> + <p> + Own Id: OTP-14189 Aux Id: ERL-348, ERL-349 </p> + </item> + <item> + <p> Improve the Erlang shell's tab-completion of long + names. </p> + <p> + Own Id: OTP-14200 Aux Id: ERL-352 </p> + </item> + <item> + <p> + The reference manual for <c>sys</c> had some faulty + information about the 'get_modules' message used by + processes where modules change dynamically during + runtime. The documentation is now corrected.</p> + <p> + Own Id: OTP-14248 Aux Id: ERL-367 </p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + Bug fixes, new features and improvements to gen_statem:</p> + <p> + A new type init_result/1 has replaced the old + init_result/0, so if you used that old type (that was + never documented) you have to change your code, which may + be regarded as a potential incompatibility.</p> + <p> + Changing callback modes after code change did not work + since the new callback mode was not recorded. This bug + has been fixed.</p> + <p> + The event types state_timeout and {call,From} could not + be generated with a {next_event,EventType,EventContent} + action since they did not pass the runtime type check. + This bug has now been corrected.</p> + <p> + State entry calls can now be repeated using (new) state + callback returns {repeat_state,...}, + {repeat_state_and_data,_} and repeat_state_and_data.</p> + <p> + There have been lots of code cleanup in particular + regarding timer handling. For example is async + cancel_timer now used. Error handling has also been + cleaned up.</p> + <p> + To align with probable future changes to the rest of + gen_*, terminate/3 has now got a fallback and + code_change/4 is not mandatory.</p> + <p> + Own Id: OTP-14114</p> + </item> + <item> + <p><c>filename:safe_relative_path/1</c> to sanitize a + relative path has been added.</p> + <p> + Own Id: OTP-14215</p> + </item> + </list> + </section> + +</section> + +<section><title>STDLIB 3.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + When a simple_one_for_one supervisor is shutting down, + and a child exits with an exit reason of the form + {shutdown, Term}, an error report was earlier printed. + This is now corrected.</p> + <p> + Own Id: OTP-13907 Aux Id: PR-1158, ERL-163 </p> + </item> + <item> + <p> Allow empty list as parameter of the fun used with + <c>dbg:fun2ms/1</c>. </p> + <p> + Own Id: OTP-13974</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + The new behaviour gen_statem has been improved with 3 new + features: the possibility to use old style non-proxy + timeouts for gen_statem:call/2,3, state entry code, and + state timeouts. These are backwards compatible. Minor + code and documentation improvements has been performed + including a borderline semantics correction of timeout + zero handling.</p> + <p> + Own Id: OTP-13929 Aux Id: PR-1170, ERL-284 </p> + </item> + </list> + </section> + +</section> + +<section><title>STDLIB 3.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + The <c>zip:unzip/1,2</c> and <c>zip:extract/1,2</c> + functions have been updated to handle directory traversal + exploits. Any element in the zip file that contains a + path that points to a directory above the top level + working directory, <c>cwd</c>, will instead be extracted + in <c>cwd</c>. An error message is printed for any such + element in the zip file during the unzip operation. The + <c>keep_old_files</c> option determines if a file will + overwrite a previous file with the same name within the + zip file.</p> + <p> + Own Id: OTP-13633</p> + </item> + <item> + <p> Correct the contracts for + <c>ets:match_object/1,3</c>. </p> + <p> + Own Id: OTP-13721 Aux Id: PR-1113 </p> + </item> + <item> + <p> + Errors in type specification and Emacs template + generation for <c>gen_statem:code_change/4</c> has been + fixed from bugs.erlang.org's Jira cases ERL-172 and + ERL-187.</p> + <p> + Own Id: OTP-13746 Aux Id: ERL-172, ERL-187 </p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + gen_statem has been changed to set the callback mode for + a server to what Module:callback_mode/0 returns. This + facilitates e.g code downgrade since the callback mode + now becomes a property of the currently active code, not + of the server process.</p> + <p> + Exception handling from Module:init/1 has also been + improved.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-13752</p> + </item> + </list> + </section> + +</section> + +<section><title>STDLIB 3.0.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> Correct a bug regarding typed records in the Erlang + shell. The bug was introduced in OTP-19.0. </p> + <p> + Own Id: OTP-13719 Aux Id: ERL-182 </p> + </item> + </list> + </section> + +</section> + <section><title>STDLIB 3.0</title> <section><title>Fixed Bugs and Malfunctions</title> @@ -511,7 +1170,7 @@ </item> <item> <p> - The <c>stdlib</c> reference manual is updated to show + The STDLIB reference manual is updated to show correct information about the return value of <c>gen_fsm:reply/2</c>.</p> <p> @@ -3046,7 +3705,7 @@ <p> Two bugs in io:format for ~F.~Ps has been corrected. When length(S) >= abs(F) > P, the precision P was incorrectly - ignored. When F == P > lenght(S) the result was + ignored. When F == P > length(S) the result was incorrectly left adjusted. Bug found by Ali Yakout who also provided a fix.</p> <p> @@ -6221,7 +6880,7 @@ documentation for <c>compile</c> on how to provide the key for encrypting, and the documentation for <c>beam_lib</c> on how to provide the key for decryption so that tools such - as the Debugger, <c>xref</c>, or <c>cover</c> can be used.</p> + as the Debugger, Xref, or Cover can be used.</p> <p>The <c>beam_lib:chunks/2</c> functions now accepts an additional chunk type <c>compile_info</c> to retrieve the compilation information directly as a term. (Thanks diff --git a/lib/stdlib/doc/src/orddict.xml b/lib/stdlib/doc/src/orddict.xml index 076b06fc38..26bbf499c6 100644 --- a/lib/stdlib/doc/src/orddict.xml +++ b/lib/stdlib/doc/src/orddict.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2000</year><year>2015</year> + <year>2000</year><year>2016</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -38,7 +38,7 @@ <p>This module provides a <c>Key</c>-<c>Value</c> dictionary. An <c>orddict</c> is a representation of a dictionary, where a list of pairs is used to store the keys and values. The list is - ordered after the keys.</p> + ordered after the keys in the <em>Erlang term order</em>.</p> <p>This module provides the same interface as the <seealso marker="dict"><c>dict(3)</c></seealso> module @@ -113,6 +113,15 @@ </func> <func> + <name name="take" arity="2"/> + <fsummary>Return value and new dictionary without element with this value.</fsummary> + <desc> + <p>This function returns value from dictionary and new dictionary without this value. + Returns <c>error</c> if the key is not present in the dictionary.</p> + </desc> + </func> + + <func> <name name="filter" arity="2"/> <fsummary>Select elements that satisfy a predicate.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/ordsets.xml b/lib/stdlib/doc/src/ordsets.xml index 148281fcf7..7b590932e4 100644 --- a/lib/stdlib/doc/src/ordsets.xml +++ b/lib/stdlib/doc/src/ordsets.xml @@ -39,7 +39,8 @@ <p>Sets are collections of elements with no duplicate elements. An <c>ordset</c> is a representation of a set, where an ordered list is used to store the elements of the set. An ordered list - is more efficient than an unordered list.</p> + is more efficient than an unordered list. Elements are ordered + according to the <em>Erlang term order</em>.</p> <p>This module provides the same interface as the <seealso marker="sets"><c>sets(3)</c></seealso> module diff --git a/lib/stdlib/doc/src/proc_lib.xml b/lib/stdlib/doc/src/proc_lib.xml index 58ca5644cf..cb152d1935 100644 --- a/lib/stdlib/doc/src/proc_lib.xml +++ b/lib/stdlib/doc/src/proc_lib.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -36,7 +36,7 @@ the <seealso marker="doc/design_principles:des_princ"> OTP Design Principles</seealso>. Specifically, the functions in this module are used by the OTP standard behaviors (for example, - <c>gen_server</c>, <c>gen_fsm</c>, and <c>gen_statem</c>) + <c>gen_server</c> and <c>gen_statem</c>) when starting new processes. The functions can also be used to start <em>special processes</em>, user-defined processes that comply to the OTP design principles. For an example, @@ -59,13 +59,19 @@ <p>When a process that is started using <c>proc_lib</c> terminates abnormally (that is, with another exit reason than <c>normal</c>, <c>shutdown</c>, or <c>{shutdown,Term}</c>), a <em>crash report</em> - is generated, which is written to terminal by the default <c>SASL</c> + is generated, which is written to terminal by the default SASL event handler. That is, the crash report is normally only visible - if the <c>SASL</c> application is started; see + if the SASL application is started; see <seealso marker="sasl:sasl_app"><c>sasl(6)</c></seealso> and section <seealso marker="sasl:error_logging">SASL Error Logging</seealso> in the SASL User's Guide.</p> + <p>Unlike in "plain Erlang", <c>proc_lib</c> processes will not generate + <em>error reports</em>, which are written to the terminal by the + emulator and do not require SASL to be started. All exceptions are + converted to <em>exits</em> which are ignored by the default + <c>error_logger</c> handler.</p> + <p>The crash report contains the previously stored information, such as ancestors and initial function, the termination reason, and information about other processes that terminate as a result diff --git a/lib/stdlib/doc/src/proplists.xml b/lib/stdlib/doc/src/proplists.xml index fe6b8cc3bf..f9a54bf804 100644 --- a/lib/stdlib/doc/src/proplists.xml +++ b/lib/stdlib/doc/src/proplists.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2002</year><year>2016</year> + <year>2002</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -344,7 +344,7 @@ split([{c, 2}, {e, 1}, a, {c, 3, 4}, d, {b, 5}, b], [a, b, c])</code> with <c>{K2, true}</c>, thus changing the name of the option and simultaneously negating the value specified by <seealso marker="#get_bool/2"> - <c>get_bool(Key, <anno>ListIn</anno></c></seealso>. + <c>get_bool(Key, <anno>ListIn</anno>)</c></seealso>. If the same <c>K1</c> occurs more than once in <c><anno>Negations</anno></c>, only the first occurrence is used.</p> <p>For example, <c>substitute_negations([{no_foo, foo}], L)</c> diff --git a/lib/stdlib/doc/src/queue.xml b/lib/stdlib/doc/src/queue.xml index a46ca47033..9f3aff03a3 100644 --- a/lib/stdlib/doc/src/queue.xml +++ b/lib/stdlib/doc/src/queue.xml @@ -401,7 +401,7 @@ </func> <func> - <name name="liat" arity="1"/>v + <name name="liat" arity="1"/> <fsummary>Remove the tail item from a queue.</fsummary> <desc> <p>Returns a queue <c><anno>Q2</anno></c> that is the result of removing diff --git a/lib/stdlib/doc/src/rand.xml b/lib/stdlib/doc/src/rand.xml index 1dcc3de000..e06d7e467d 100644 --- a/lib/stdlib/doc/src/rand.xml +++ b/lib/stdlib/doc/src/rand.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2015</year> + <year>2015</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -41,27 +41,82 @@ Sebastiano Vigna</url>. The normal distribution algorithm uses the <url href="http://www.jstatsoft.org/v05/i08">Ziggurat Method by Marsaglia and Tsang</url>.</p> + <p>For some algorithms, jump functions are provided for generating + non-overlapping sequences for parallel computations. + The jump functions perform calculations + equivalent to perform a large number of repeated calls + for calculating new states. </p> <p>The following algorithms are provided:</p> <taglist> - <tag><c>exsplus</c></tag> + <tag><c>exrop</c></tag> <item> - <p>Xorshift116+, 58 bits precision and period of 2^116-1</p> + <p>Xoroshiro116+, 58 bits precision and period of 2^116-1</p> + <p>Jump function: equivalent to 2^64 calls</p> </item> - <tag><c>exs64</c></tag> + <tag><c>exs1024s</c></tag> <item> - <p>Xorshift64*, 64 bits precision and a period of 2^64-1</p> + <p>Xorshift1024*, 64 bits precision and a period of 2^1024-1</p> + <p>Jump function: equivalent to 2^512 calls</p> </item> - <tag><c>exs1024</c></tag> + <tag><c>exsp</c></tag> <item> - <p>Xorshift1024*, 64 bits precision and a period of 2^1024-1</p> + <p>Xorshift116+, 58 bits precision and period of 2^116-1</p> + <p>Jump function: equivalent to 2^64 calls</p> + <p> + This is a corrected version of the previous default algorithm, + that now has been superseeded by Xoroshiro116+ (<c>exrop</c>). + Since there is no native 58 bit rotate instruction this + algorithm executes a little (say < 15%) faster than <c>exrop</c>. + See the + <url href="http://xorshift.di.unimi.it">algorithms' homepage</url>. + </p> </item> </taglist> - <p>The default algorithm is <c>exsplus</c>. If a specific algorithm is + <p> + The default algorithm is <c>exrop</c> (Xoroshiro116+). + If a specific algorithm is required, ensure to always use <seealso marker="#seed-1"> - <c>seed/1</c></seealso> to initialize the state.</p> + <c>seed/1</c></seealso> to initialize the state. + </p> + + <p> + Undocumented (old) algorithms are deprecated but still implemented + so old code relying on them will produce + the same pseudo random sequences as before. + </p> + + <note> + <p> + There were a number of problems in the implementation + of the now undocumented algorithms, which is why + they are deprecated. The new algorithms are a bit slower + but do not have these problems: + </p> + <p> + Uniform integer ranges had a skew in the probability distribution + that was not noticable for small ranges but for large ranges + less than the generator's precision the probability to produce + a low number could be twice the probability for a high. + </p> + <p> + Uniform integer ranges larger than or equal to the generator's + precision used a floating point fallback that only calculated + with 52 bits which is smaller than the requested range + and therefore were not all numbers in the requested range + even possible to produce. + </p> + <p> + Uniform floats had a non-uniform density so small values + i.e less than 0.5 had got smaller intervals decreasing + as the generated value approached 0.0 although still uniformly + distributed for sufficiently large subranges. The new algorithms + produces uniformly distributed floats on the form N * 2.0^(-53) + hence equally spaced. + </p> + </note> <p>Every time a random number is requested, a state is used to calculate it and a new state is produced. The state can either be @@ -91,19 +146,19 @@ R1 = rand:uniform(),</pre> <p>Use a specified algorithm:</p> <pre> -_ = rand:seed(exs1024), +_ = rand:seed(exs1024s), R2 = rand:uniform(),</pre> <p>Use a specified algorithm with a constant seed:</p> <pre> -_ = rand:seed(exs1024, {123, 123534, 345345}), +_ = rand:seed(exs1024s, {123, 123534, 345345}), R3 = rand:uniform(),</pre> <p>Use the functional API with a non-constant seed:</p> <pre> -S0 = rand:seed_s(exsplus), +S0 = rand:seed_s(exrop), {R4, S1} = rand:uniform_s(S0),</pre> <p>Create a standard normal deviate:</p> @@ -111,28 +166,93 @@ S0 = rand:seed_s(exsplus), <pre> {SND0, S2} = rand:normal_s(S1),</pre> + <p>Create a normal deviate with mean -3 and variance 0.5:</p> + + <pre> +{ND0, S3} = rand:normal_s(-3, 0.5, S2),</pre> + <note> - <p>This random number generator is not cryptographically - strong. If a strong cryptographic random number generator is - needed, use one of functions in the - <seealso marker="crypto:crypto"><c>crypto</c></seealso> - module, for example, <seealso marker="crypto:crypto"> - <c>crypto:strong_rand_bytes/1</c></seealso>.</p> + <p>The builtin random number generator algorithms are not + cryptographically strong. If a cryptographically strong + random number generator is needed, use something like + <seealso marker="crypto:crypto#rand_seed-0"><c>crypto:rand_seed/0</c></seealso>. + </p> </note> + <p> + For all these generators the lowest bit(s) has got + a slightly less random behaviour than all other bits. + 1 bit for <c>exrop</c> (and <c>exsp</c>), + and 3 bits for <c>exs1024s</c>. + See for example the explanation in the + <url href="http://xoroshiro.di.unimi.it/xoroshiro128plus.c"> + Xoroshiro128+ + </url> + generator source code: + </p> + <pre> +Beside passing BigCrush, this generator passes the PractRand test suite +up to (and included) 16TB, with the exception of binary rank tests, +which fail due to the lowest bit being an LFSR; all other bits pass all +tests. We suggest to use a sign test to extract a random Boolean value.</pre> + <p> + If this is a problem; to generate a boolean + use something like this: + </p> + <pre>(rand:uniform(16) > 8)</pre> + <p> + And for a general range, with <c>N = 1</c> for <c>exrop</c>, + and <c>N = 3</c> for <c>exs1024s</c>: + </p> + <pre>(((rand:uniform(Range bsl N) - 1) bsr N) + 1)</pre> + <p> + The floating point generating functions in this module + waste the lowest bits when converting from an integer + so they avoid this snag. + </p> + + </description> <datatypes> <datatype> + <name name="builtin_alg"/> + </datatype> + <datatype> <name name="alg"/> </datatype> <datatype> + <name name="alg_handler"/> + </datatype> + <datatype> + <name name="alg_state"/> + </datatype> + <datatype> <name name="state"/> <desc><p>Algorithm-dependent state.</p></desc> </datatype> <datatype> <name name="export_state"/> - <desc><p>Algorithm-dependent state that can be printed or saved to - file.</p></desc> + <desc> + <p> + Algorithm-dependent state that can be printed or saved to file. + </p> + </desc> + </datatype> + <datatype> + <name name="exs64_state"/> + <desc><p>Algorithm specific internal state</p></desc> + </datatype> + <datatype> + <name name="exsplus_state"/> + <desc><p>Algorithm specific internal state</p></desc> + </datatype> + <datatype> + <name name="exs1024_state"/> + <desc><p>Algorithm specific internal state</p></desc> + </datatype> + <datatype> + <name name="exrop_state"/> + <desc><p>Algorithm specific internal state</p></desc> </datatype> </datatypes> @@ -156,6 +276,33 @@ S0 = rand:seed_s(exsplus), </func> <func> + <name name="jump" arity="0"/> + <fsummary>Return the seed after performing jump calculation + to the state in the process dictionary.</fsummary> + <desc><marker id="jump-0" /> + <p>Returns the state + after performing jump calculation + to the state in the process dictionary.</p> + <p>This function generates a <c>not_implemented</c> error exception + when the jump function is not implemented for + the algorithm specified in the state + in the process dictionary.</p> + </desc> + </func> + + <func> + <name name="jump" arity="1"/> + <fsummary>Return the seed after performing jump calculation.</fsummary> + <desc><marker id="jump-1" /> + <p>Returns the state after performing jump calculation + to the given state. </p> + <p>This function generates a <c>not_implemented</c> error exception + when the jump function is not implemented for + the algorithm specified in the state.</p> + </desc> + </func> + + <func> <name name="normal" arity="0"/> <fsummary>Return a standard normal distributed random float.</fsummary> <desc> @@ -166,6 +313,15 @@ S0 = rand:seed_s(exsplus), </func> <func> + <name name="normal" arity="2"/> + <fsummary>Return a normal distributed random float.</fsummary> + <desc> + <p>Returns a normal N(Mean, Variance) deviate float + and updates the state in the process dictionary.</p> + </desc> + </func> + + <func> <name name="normal_s" arity="1"/> <fsummary>Return a standard normal distributed random float.</fsummary> <desc> @@ -176,12 +332,24 @@ S0 = rand:seed_s(exsplus), </func> <func> + <name name="normal_s" arity="3"/> + <fsummary>Return a normal distributed random float.</fsummary> + <desc> + <p>Returns, for a specified state, a normal N(Mean, Variance) + deviate float and a new state.</p> + </desc> + </func> + + <func> <name name="seed" arity="1"/> <fsummary>Seed random number generator.</fsummary> <desc> <marker id="seed-1"/> - <p>Seeds random number generation with the specifed algorithm and - time-dependent data if <anno>AlgOrExpState</anno> is an algorithm.</p> + <p> + Seeds random number generation with the specifed algorithm and + time-dependent data if <c><anno>AlgOrStateOrExpState</anno></c> + is an algorithm. + </p> <p>Otherwise recreates the exported seed in the process dictionary, and returns the state. See also <seealso marker="#export_seed-0"><c>export_seed/0</c></seealso>.</p> @@ -201,8 +369,11 @@ S0 = rand:seed_s(exsplus), <name name="seed_s" arity="1"/> <fsummary>Seed random number generator.</fsummary> <desc> - <p>Seeds random number generation with the specifed algorithm and - time-dependent data if <anno>AlgOrExpState</anno> is an algorithm.</p> + <p> + Seeds random number generation with the specifed algorithm and + time-dependent data if <c><anno>AlgOrStateOrExpState</anno></c> + is an algorithm. + </p> <p>Otherwise recreates the exported seed and returns the state. See also <seealso marker="#export_seed-0"> <c>export_seed/0</c></seealso>.</p> @@ -223,7 +394,7 @@ S0 = rand:seed_s(exsplus), <fsummary>Return a random float.</fsummary> <desc><marker id="uniform-0"/> <p>Returns a random float uniformly distributed in the value - range <c>0.0 < <anno>X</anno> < 1.0</c> and + range <c>0.0 =< <anno>X</anno> < 1.0</c> and updates the state in the process dictionary.</p> </desc> </func> @@ -234,7 +405,7 @@ S0 = rand:seed_s(exsplus), <desc><marker id="uniform-1"/> <p>Returns, for a specified integer <c><anno>N</anno> >= 1</c>, a random integer uniformly distributed in the value range - <c>1 <= <anno>X</anno> <= <anno>N</anno></c> and + <c>1 =< <anno>X</anno> =< <anno>N</anno></c> and updates the state in the process dictionary.</p> </desc> </func> @@ -244,7 +415,7 @@ S0 = rand:seed_s(exsplus), <fsummary>Return a random float.</fsummary> <desc> <p>Returns, for a specified state, random float - uniformly distributed in the value range <c>0.0 < + uniformly distributed in the value range <c>0.0 =< <anno>X</anno> < 1.0</c> and a new state.</p> </desc> </func> @@ -255,7 +426,7 @@ S0 = rand:seed_s(exsplus), <desc> <p>Returns, for a specified integer <c><anno>N</anno> >= 1</c> and a state, a random integer uniformly distributed in the value - range <c>1 <= <anno>X</anno> <= <anno>N</anno></c> and a + range <c>1 =< <anno>X</anno> =< <anno>N</anno></c> and a new state.</p> </desc> </func> diff --git a/lib/stdlib/doc/src/re.xml b/lib/stdlib/doc/src/re.xml index 7f4f0aa18c..078ca0e38c 100644 --- a/lib/stdlib/doc/src/re.xml +++ b/lib/stdlib/doc/src/re.xml @@ -5,7 +5,7 @@ <header> <copyright> <year>2007</year> - <year>2016</year> + <year>2017</year> <holder>Ericsson AB, All Rights Reserved</holder> </copyright> <legalnotice> @@ -45,9 +45,10 @@ <p>The matching algorithms of the library are based on the PCRE library, but not all of the PCRE library is interfaced and - some parts of the library go beyond what PCRE offers. The sections of - the PCRE documentation that are relevant to this module are included - here.</p> + some parts of the library go beyond what PCRE offers. Currently + PCRE version 8.40 (release date 2017-01-11) is used. The sections + of the PCRE documentation that are relevant to this module are + included here.</p> <note> <p>The Erlang literal syntax for strings uses the "\" @@ -78,6 +79,14 @@ <funcs> <func> + <name name="version" arity="0"/> + <fsummary>Gives the PCRE version of the system in a string format</fsummary> + <desc> + <p>The return of this function is a string with the PCRE version of the system that was used in the Erlang/OTP compilation.</p> + </desc> + </func> + + <func> <name name="compile" arity="1"/> <fsummary>Compile a regular expression into a match program</fsummary> <desc> @@ -149,13 +158,25 @@ </item> <tag><c>extended</c></tag> <item> - <p>Whitespace data characters in the pattern are ignored except - when escaped or inside a character class. Whitespace does not - include character 'vt' (ASCII 11). Characters between an - unescaped <c>#</c> outside a character class and the next newline, - inclusive, are also ignored. This is equivalent to Perl option - <c>/x</c> and can be changed within a pattern by a <c>(?x)</c> - option setting.</p> + <p>If this option is set, most white space characters in the + pattern are totally ignored except when escaped or inside a + character class. However, white space is not allowed within + sequences such as <c>(?></c> that introduce various + parenthesized subpatterns, nor within a numerical quantifier + such as <c>{1,3}</c>. However, ignorable white space is permitted + between an item and a following quantifier and between a + quantifier and a following + that indicates possessiveness. + </p> + <p>White space did not used to include the VT character (code + 11), because Perl did not treat this character as white space. + However, Perl changed at release 5.18, so PCRE followed at + release 8.34, and VT is now treated as white space. + </p> + <p>This also causes characters between an unescaped # + outside a character class and the next newline, inclusive, to + be ignored. This is equivalent to Perl's <c>/x</c> option, and it + can be changed within a pattern by a <c>(?x)</c> option setting. + </p> <p>With this option, comments inside complicated patterns can be included. However, notice that this applies only to data characters. Whitespace characters can never appear within special @@ -1321,6 +1342,8 @@ re:split("Erlang","[lg]",[{return,list},{parts,4}]).</code> VM. Notice that the recursion limit does not affect the stack depth of the VM, as PCRE for Erlang is compiled in such a way that the match function never does recursion on the C stack.</p> + <p>Note that <c>LIMIT_MATCH</c> and <c>LIMIT_RECURSION</c> can only reduce + the value of the limits set by the caller, not increase them.</p> </section> <section> @@ -1444,12 +1467,17 @@ Pattern PCRE matches Perl matches <tag>\n</tag><item>Line feed (hex 0A)</item> <tag>\r</tag><item>Carriage return (hex 0D)</item> <tag>\t</tag><item>Tab (hex 09)</item> + <tag>\0dd</tag><item>Character with octal code 0dd</item> <tag>\ddd</tag><item>Character with octal code ddd, or back reference </item> + <tag>\o{ddd..}</tag><item>character with octal code ddd..</item> <tag>\xhh</tag><item>Character with hex code hh</item> <tag>\x{hhh..}</tag><item>Character with hex code hhh..</item> </taglist> + <note><p>Note that \0dd is always an octal code, and that \8 and \9 are + the literal characters "8" and "9".</p></note> + <p>The precise effect of \cx on ASCII characters is as follows: if x is a lowercase letter, it is converted to upper case. Then bit 6 of the character (hex 40) is inverted. Thus \cA to \cZ become hex 01 to hex 1A @@ -1461,50 +1489,38 @@ Pattern PCRE matches Perl matches <p>The \c facility was designed for use with ASCII characters, but with the extension to Unicode it is even less useful than it once was.</p> - <p>By default, after \x, from zero to two hexadecimal digits are read - (letters can be in upper or lower case). Any number of hexadecimal digits - can appear between \x{ and }, but the character code is constrained as - follows:</p> - - <taglist> - <tag>8-bit non-Unicode mode</tag> - <item>< 0x100</item> - <tag>8-bit UTF-8 mode</tag> - <item>< 0x10ffff and a valid code point</item> - </taglist> - - <p>Invalid Unicode code points are the range 0xd800 to 0xdfff (the so-called - "surrogate" code points), and 0xffef.</p> - - <p>If characters other than hexadecimal digits appear between \x{ and }, - or if there is no terminating }, this form of escape is not recognized. - Instead, the initial \x is interpreted as a basic hexadecimal escape, - with no following digits, giving a character whose value is zero.</p> - - <p>Characters whose value is < 256 can be defined by either of the two - syntaxes for \x. There is no difference in the way they are handled. For - example, \xdc is the same as \x{dc}.</p> - <p>After \0 up to two further octal digits are read. If there are fewer than - two digits, only those that are present are used. Thus the sequence - \0\x\07 specifies two binary zeros followed by a BEL character (code value - 7). Ensure to supply two digits after the initial zero if the pattern - character that follows is itself an octal digit.</p> + two digits, just those that are present are used. Thus the sequence + \0\x\015 specifies two binary zeros followed by a CR character (code value + 13). Make sure you supply two digits after the initial zero if the pattern + character that follows is itself an octal digit.</p> + + <p>The escape \o must be followed by a sequence of octal digits, enclosed + in braces. An error occurs if this is not the case. This escape is a recent + addition to Perl; it provides way of specifying character code points as + octal numbers greater than 0777, and it also allows octal numbers and back + references to be unambiguously specified.</p> + + <p>For greater clarity and unambiguity, it is best to avoid following \ by + a digit greater than zero. Instead, use \o{} or \x{} to specify character + numbers, and \g{} to specify back references. The following paragraphs + describe the old, ambiguous syntax.</p> <p>The handling of a backslash followed by a digit other than 0 is - complicated. Outside a character class, PCRE reads it and any following - digits as a decimal number. If the number is < 10, or if there have + complicated, and Perl has changed in recent releases, causing PCRE also + to change. Outside a character class, PCRE reads the digit and any following + digits as a decimal number. If the number is < 8, or if there have been at least that many previous capturing left parentheses in the expression, the entire sequence is taken as a <em>back reference</em>. A description of how this works is provided later, following the discussion of parenthesized subpatterns.</p> - <p>Inside a character class, or if the decimal number is > 9 and there - have not been that many capturing subpatterns, PCRE re-reads up to three - octal digits following the backslash, and uses them to generate a data - character. Any subsequent digits stand for themselves. The value of the - character is constrained in the same way as characters specified in - hexadecimal. For example:</p> + <p>Inside a character class, or if the decimal number following \ is > + 7 and there have not been that many capturing subpatterns, PCRE handles + \8 and \9 as the literal characters "8" and "9", and otherwise re-reads + up to three octal digits following the backslash, and using them to + generate a data character. Any subsequent digits stand for themselves. + For example:</p> <taglist> <tag>\040</tag> @@ -1526,12 +1542,38 @@ Pattern PCRE matches Perl matches <tag>\377</tag> <item>Can be a back reference, otherwise value 255 (decimal)</item> <tag>\81</tag> - <item>Either a back reference, or a binary zero followed by the two - characters "8" and "1"</item> + <item>Either a back reference, or the two characters "8" and "1"</item> </taglist> - <p>Notice that octal values >= 100 must not be introduced by a leading - zero, as no more than three octal digits are ever read.</p> + <p>Notice that octal values >= 100 that are specified using this syntax + must not be introduced by a leading zero, as no more than three octal digits + are ever read.</p> + + <p>By default, after \x that is not followed by {, from zero to two + hexadecimal digits are read (letters can be in upper or lower case). Any + number of hexadecimal digits may appear between \x{ and }. If a character + other than a hexadecimal digit appears between \x{ and }, or if there is no + terminating }, an error occurs. + </p> + + <p>Characters whose value is less than 256 can be defined by either of the + two syntaxes for \x. There is no difference in the way they are handled. For + example, \xdc is exactly the same as \x{dc}.</p> + + <p><em>Constraints on character values</em></p> + + <p>Characters that are specified using octal or hexadecimal numbers are + limited to certain values, as follows:</p> + <taglist> + <tag>8-bit non-UTF mode</tag> + <item><p>< 0x100</p></item> + <tag>8-bit UTF-8 mode</tag> + <item><p>< 0x10ffff and a valid codepoint</p></item> + </taglist> + <p>Invalid Unicode codepoints are the range 0xd800 to 0xdfff (the + so-called "surrogate" codepoints), and 0xffef.</p> + + <p><em>Escape sequences in character classes</em></p> <p>All the sequences that define a single character value can be used both inside and outside character classes. Also, inside a character class, \b @@ -1597,11 +1639,14 @@ Pattern PCRE matches Perl matches appropriate type. If the current matching point is at the end of the subject string, all fail, as there is no character to match.</p> - <p>For compatibility with Perl, \s does not match the VT character - (code 11). This makes it different from the Posix "space" class. The \s - characters are HT (9), LF (10), FF (12), CR (13), and space (32). If "use - locale;" is included in a Perl script, \s can match the VT character. In - PCRE, it never does.</p> + <p>For compatibility with Perl, \s did not used to match the VT character (code + 11), which made it different from the the POSIX "space" class. However, Perl + added VT at release 5.18, and PCRE followed suit at release 8.34. The default + \s characters are now HT (9), LF (10), VT (11), FF (12), CR (13), and space + (32), which are defined as white space in the "C" locale. This list may vary if + locale-specific matching is taking place. For example, in some locales the + "non-breaking space" character (\xA0) is recognized as white space, and in + others the VT character is not.</p> <p>A "word" character is an underscore or any character that is a letter or a digit. By default, the definition of letters and digits is controlled by @@ -1619,9 +1664,9 @@ Pattern PCRE matches Perl matches <taglist> <tag>\d</tag><item>Any character that \p{Nd} matches (decimal digit) </item> - <tag>\s</tag><item>Any character that \p{Z} matches, plus HT, LF, FF, CR + <tag>\s</tag><item>Any character that \p{Z} or \h or \v </item> - <tag>\w</tag><item>Any character that \p{L} or \p{N} matches, plus + <tag>\w</tag><item>Any character that matches \p{L} or \p{N} matches, plus underscore</item> </taglist> @@ -1769,6 +1814,7 @@ Pattern PCRE matches Perl matches <item>Avestan</item> <item>Balinese</item> <item>Bamum</item> + <item>Bassa_Vah</item> <item>Batak</item> <item>Bengali</item> <item>Bopomofo</item> @@ -1777,6 +1823,7 @@ Pattern PCRE matches Perl matches <item>Buhid</item> <item>Canadian_Aboriginal</item> <item>Carian</item> + <item>Caucasian_Albanian</item> <item>Chakma</item> <item>Cham</item> <item>Cherokee</item> @@ -1787,11 +1834,14 @@ Pattern PCRE matches Perl matches <item>Cyrillic</item> <item>Deseret</item> <item>Devanagari</item> + <item>Duployan</item> <item>Egyptian_Hieroglyphs</item> + <item>Elbasan</item> <item>Ethiopic</item> <item>Georgian</item> <item>Glagolitic</item> <item>Gothic</item> + <item>Grantha</item> <item>Greek</item> <item>Gujarati</item> <item>Gurmukhi</item> @@ -1811,40 +1861,56 @@ Pattern PCRE matches Perl matches <item>Kayah_Li</item> <item>Kharoshthi</item> <item>Khmer</item> + <item>Khojki</item> + <item>Khudawadi</item> <item>Lao</item> <item>Latin</item> <item>Lepcha</item> <item>Limbu</item> + <item>Linear_A</item> <item>Linear_B</item> <item>Lisu</item> <item>Lycian</item> <item>Lydian</item> + <item>Mahajani</item> <item>Malayalam</item> <item>Mandaic</item> + <item>Manichaean</item> <item>Meetei_Mayek</item> + <item>Mende_Kikakui</item> <item>Meroitic_Cursive</item> <item>Meroitic_Hieroglyphs</item> <item>Miao</item> + <item>Modi</item> <item>Mongolian</item> + <item>Mro</item> <item>Myanmar</item> + <item>Nabataean</item> <item>New_Tai_Lue</item> <item>Nko</item> <item>Ogham</item> + <item>Ol_Chiki</item> <item>Old_Italic</item> + <item>Old_North_Arabian</item> + <item>Old_Permic</item> <item>Old_Persian</item> <item>Oriya</item> <item>Old_South_Arabian</item> <item>Old_Turkic</item> - <item>Ol_Chiki</item> <item>Osmanya</item> + <item>Pahawh_Hmong</item> + <item>Palmyrene</item> + <item>Pau_Cin_Hau</item> <item>Phags_Pa</item> <item>Phoenician</item> + <item>Psalter_Pahlavi</item> <item>Rejang</item> <item>Runic</item> <item>Samaritan</item> <item>Saurashtra</item> <item>Sharada</item> <item>Shavian</item> + <item>Siddham</item> <item>Sinhala</item> <item>Sora_Sompeng</item> <item>Sundanese</item> @@ -1862,8 +1928,10 @@ Pattern PCRE matches Perl matches <item>Thai</item> <item>Tibetan</item> <item>Tifinagh</item> + <item>Tirhuta</item> <item>Ugaritic</item> <item>Vai</item> + <item>Warang_Citi</item> <item>Yi</item> </list> @@ -2001,10 +2069,10 @@ Pattern PCRE matches Perl matches <p>In addition to the standard Unicode properties described earlier, PCRE supports four more that make it possible to convert traditional escape - sequences, such as \w and \s, and Posix character classes to use Unicode + sequences, such as \w and \s to use Unicode properties. PCRE uses these non-standard, non-Perl properties internally - when <c>PCRE_UCP</c> is set. However, they can also be used explicitly. - The properties are as follows:</p> + when the <c>ucp</c> option is passed. However, they can also be used + explicitly. The properties are as follows:</p> <taglist> <tag>Xan</tag> @@ -2030,6 +2098,16 @@ Pattern PCRE matches Perl matches </item> </taglist> + <p>Perl and POSIX space are now the same. Perl added VT to its space + character set at release 5.18 and PCRE changed at release 8.34.</p> + + <p>Xan matches characters that have either the L (letter) or the N (number) + property. Xps matches the characters tab, linefeed, vertical tab, form feed, + or carriage return, and any other character that has the Z (separator) + property. Xsp is the same as Xps; it used to exclude vertical tab, for Perl + compatibility, but Perl changed, and so PCRE followed at release 8.34. Xwd + matches the same characters as Xan, plus underscore. + </p> <p>There is another non-standard property, Xuc, which matches any character that can be represented by a Universal Character Name in C++ and other programming languages. These are the characters $, @, ` (grave accent), @@ -2062,7 +2140,9 @@ foo\Kbar</code> <p>Perl documents that the use of \K within assertions is "not well defined". In PCRE, \K is acted upon when it occurs inside positive - assertions, but is ignored in negative assertions.</p> + assertions, but is ignored in negative assertions. Note that when a + pattern such as (?=ab\K) matches, the reported start of the match can + be greater than the end of the match.</p> <p><em>Simple Assertions</em></p> @@ -2301,7 +2381,8 @@ foo\Kbar</code> m, inclusive. If a minus character is required in a class, it must be escaped with a backslash or appear in a position where it cannot be interpreted as indicating a range, typically as the first or last - character in the class.</p> + character in the class, or immediately after a range. For example, [b-d-z] + matches letters in the range b to d, a hyphen character, or z.</p> <p>The literal character "]" cannot be the end character of a range. A pattern such as [W-]46] is interpreted as a class of two characters ("W" @@ -2311,6 +2392,11 @@ foo\Kbar</code> followed by two other characters. The octal or hexadecimal representation of "]" can also be used to end a range.</p> + <p>An error is generated if a POSIX character class (see below) or an + escape sequence other than one that defines a single character appears at + a point where a range ending character is expected. For example, [z-\xff] + is valid, but [A-\d] and [A-[:digit:]] are not.</p> + <p>Ranges operate in the collating sequence of character values. They can also be used for characters specified numerically, for example, [\000-\037]. Ranges can include any characters that are valid for the @@ -2353,7 +2439,8 @@ foo\Kbar</code> range)</item> <item>Circumflex (only at the start)</item> <item>Opening square bracket (only when it can be interpreted as - introducing a Posix class name; see the next section)</item> + introducing a Posix class name, or for a special compatibility + feature; see the next two sections)</item> <item>Terminating closing square bracket</item> </list> @@ -2385,16 +2472,18 @@ foo\Kbar</code> <tag>print</tag><item>Printing characters, including space</item> <tag>punct</tag><item>Printing characters, excluding letters, digits, and space</item> - <tag>space</tag><item>Whitespace (not quite the same as \s)</item> + <tag>space</tag><item>Whitespace (the same as \s from PCRE 8.34)</item> <tag>upper</tag><item>Uppercase letters</item> <tag>word</tag><item>"Word" characters (same as \w)</item> <tag>xdigit</tag><item>Hexadecimal digits</item> </taglist> - <p>The "space" characters are HT (9), LF (10), VT (11), FF (12), CR (13), - and space (32). Notice that this list includes the VT character (code 11). - This makes "space" different to \s, which does not include VT (for Perl - compatibility).</p> + <p>The default "space" characters are HT (9), LF (10), VT (11), FF (12), + CR (13), and space (32). If locale-specific matching is taking place, the + list of space characters may be different; there may be fewer or more of + them. "Space" used to be different to \s, which did not include VT, for + Perl compatibility. However, Perl changed at release 5.18, and PCRE followed + at release 8.34. "Space" and \s now match the same set of characters.</p> <p>The name "word" is a Perl extension, and "blank" is a GNU extension from Perl 5.8. Another Perl extension is negation, which is indicated by a ^ @@ -2408,11 +2497,11 @@ foo\Kbar</code> "ch" is a "collating element", but these are not supported, and an error is given if they are encountered.</p> - <p>By default, in UTF modes, characters with values > 255 do not match + <p>By default, characters with values > 255 do not match any of the Posix character classes. However, if option <c>PCRE_UCP</c> is passed to <c>pcre_compile()</c>, some of the classes are changed so that - Unicode character properties are used. This is achieved by replacing the - Posix classes by other sequences, as follows:</p> + Unicode character properties are used. This is achieved by replacing + certain Posix classes by other sequences, as follows:</p> <taglist> <tag>[:alnum:]</tag><item>Becomes <em>\p{Xan}</em></item> @@ -2425,9 +2514,49 @@ foo\Kbar</code> <tag>[:word:]</tag><item>Becomes <em>\p{Xwd}</em></item> </taglist> - <p>Negated versions, such as [:^alpha:], use \P instead of \p. The other - Posix classes are unchanged, and match only characters with code points - < 256.</p> + <p>Negated versions, such as [:^alpha:], use \P instead of \p. Three other + POSIX classes are handled specially in UCP mode:</p> + <taglist> + <tag>[:graph:]</tag> + <item><p>This matches characters that have glyphs that mark the page + when printed. In Unicode property terms, it matches all characters with + the L, M, N, P, S, or Cf properties, except for:</p> + <taglist> + <tag>U+061C</tag><item><p>Arabic Letter Mark</p></item> + <tag>U+180E</tag><item><p>Mongolian Vowel Separator</p></item> + <tag>U+2066 - U+2069</tag><item><p>Various "isolate"s</p></item> + </taglist> + </item> + <tag>[:print:]</tag> + <item><p>This matches the same characters as [:graph:] plus space + characters that are not controls, that is, characters with the Zs + property.</p></item> + <tag>[:punct:]</tag><item><p>This matches all characters that have + the Unicode P (punctuation) property, plus those characters whose code + points are less than 128 that have the S (Symbol) property.</p></item> + </taglist> + <p>The other POSIX classes are unchanged, and match only characters with + code points less than 128. + </p> + + <p><em>Compatibility Feature for Word Boundaries</em></p> + + <p>In the POSIX.2 compliant library that was included in 4.4BSD Unix, + the ugly syntax [[:<:]] and [[:>:]] is used for matching "start + of word" and "end of word". PCRE treats these items as follows:</p> + <taglist> + <tag>[[:<:]]</tag><item><p>is converted to \b(?=\w)</p></item> + <tag>[[:>:]]</tag><item><p>is converted to \b(?<=\w)</p></item> + </taglist> + <p>Only these exact character sequences are recognized. A sequence such as + [a[:<:]b] provokes error for an unrecognized POSIX class name. This + support is not compatible with Perl. It is provided to help migrations from + other environments, and is best not used in any new patterns. Note that \b + matches at the start and the end of a word (see "Simple assertions" above), + and in a Perl-style pattern the preceding or following character normally + shows which is wanted, without the need for the assertions that are used + above in order to give exactly the POSIX behaviour.</p> + </section> <section> @@ -2476,8 +2605,7 @@ gilbert|sullivan</code> <p>When one of these option changes occurs at top-level (that is, not inside subpattern parentheses), the change applies to the remainder of the - pattern that follows. If the change is placed right at the start of a - pattern, PCRE extracts it into the global options.</p> + pattern that follows.</p> <p>An option change within a subpattern (see section <seealso marker="#sect11">Subpatterns</seealso>) affects only that part of the subpattern that follows it. So, the following matches abc and aBc and @@ -2645,9 +2773,9 @@ the ((?:red|white) (king|queen))</code> parentheses from other parts of the pattern, such as back references, recursion, and conditions, can be made by name and by number.</p> - <p>Names consist of up to 32 alphanumeric characters and underscores. Named - capturing parentheses are still allocated numbers as well as names, - exactly as if the names were not present. + <p>Names consist of up to 32 alphanumeric characters and underscores, but + must start with a non-digit. Named capturing parentheses are still allocated + numbers as well as names, exactly as if the names were not present. The <c>capture</c> specification to <seealso marker="#run/3"> <c>run/3</c></seealso> can use named values if they are present in the regular expression.</p> @@ -3118,7 +3246,14 @@ aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa</code> purposes of numbering the capturing subpatterns in the whole pattern. However, substring capturing is done only for positive assertions. (Perl sometimes, but not always, performs capturing in negative assertions.)</p> - + <warning> + <p>If a positive assertion containing one or more capturing subpatterns + succeeds, but failure to match later in the pattern causes backtracking over + this assertion, the captures within the assertion are reset only if no higher + numbered captures are already set. This is, unfortunately, a fundamental + limitation of the current implementation, and as PCRE1 is now in + maintenance-only status, it is unlikely ever to change.</p> + </warning> <p>For compatibility with Perl, assertion subpatterns can be repeated. However, it makes no sense to assert the same thing many times, the side effect of capturing parentheses can occasionally be useful. In practice, @@ -3371,12 +3506,7 @@ abcd$</code> <p>Perl uses the syntax (?(<name>)...) or (?('name')...) to test for a used subpattern by name. For compatibility with earlier versions of PCRE, which had this facility before Perl, the syntax (?(name)...) is also - recognized. However, there is a possible ambiguity with this syntax, as - subpattern names can consist entirely of digits. PCRE looks first for a - named subpattern; if it cannot find one and the name consists entirely of - digits, PCRE looks for a subpattern of that number, which must be > 0. - Using subpattern names that consist entirely of digits is not - recommended.</p> + recognized.</p> <p>Rewriting the previous example to use a named subpattern gives:</p> @@ -3958,11 +4088,13 @@ a+(*COMMIT)b</code> 2> re:run("xyzabc","(*COMMIT)abc",[{capture,all,list},no_start_optimize]). nomatch</code> - <p>PCRE knows that any match must start with "a", so the optimization skips - along the subject to "a" before running the first match attempt, which - succeeds. When the optimization is disabled by option - <c>no_start_optimize</c>, the match starts at "x" and so the (*COMMIT) - causes it to fail without trying any other starting points.</p> + <p>For this pattern, PCRE knows that any match must start with "a", so the + optimization skips along the subject to "a" before applying the pattern to the + first set of data. The match attempt then succeeds. In the second call the + <c>no_start_optimize</c> disables the optimization that skips along to the + first character. The pattern is now applied starting at "x", and so the + (*COMMIT) causes the match to fail without trying any other starting + points.</p> <p>The following verb causes the match to fail at the current starting position in the subject if there is a later matching failure that causes @@ -4138,7 +4270,7 @@ A (B(*THEN)C | (*FAIL)) | D</code> ...(*COMMIT)(*PRUNE)...</code> <p>If there is a matching failure to the right, backtracking onto (*PRUNE) - cases it to be triggered, and its action is taken. There can never be a + causes it to be triggered, and its action is taken. There can never be a backtrack onto (*COMMIT).</p> <p><em>Backtracking Verbs in Repeated Groups</em></p> diff --git a/lib/stdlib/doc/src/sets.xml b/lib/stdlib/doc/src/sets.xml index f7668af1ed..4934bed365 100644 --- a/lib/stdlib/doc/src/sets.xml +++ b/lib/stdlib/doc/src/sets.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2000</year><year>2015</year> + <year>2000</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -40,7 +40,7 @@ <p>This module provides the same interface as the <seealso marker="ordsets"><c>ordsets(3)</c></seealso> module - but with a defined representation. One difference is + but with an undefined representation. One difference is that while this module considers two elements as different if they do not match (<c>=:=</c>), <c>ordsets</c> considers two elements as different if and only if they do not compare equal (<c>==</c>).</p> diff --git a/lib/stdlib/doc/src/shell.xml b/lib/stdlib/doc/src/shell.xml index d6e8036d4e..2593d3690b 100644 --- a/lib/stdlib/doc/src/shell.xml +++ b/lib/stdlib/doc/src/shell.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -165,12 +165,12 @@ <item> <p>Evaluates <c>shell_default:help()</c>.</p> </item> - <tag><c>c(File)</c></tag> + <tag><c>c(Mod)</c></tag> <item> - <p>Evaluates <c>shell_default:c(File)</c>. This compiles - and loads code in <c>File</c> and purges old versions of - code, if necessary. Assumes that the file and module names - are the same.</p> + <p>Evaluates <c>shell_default:c(Mod)</c>. This compiles and + loads the module <c>Mod</c> and purges old versions of the + code, if necessary. <c>Mod</c> can be either a module name or a + a source file path, with or without <c>.erl</c> extension.</p> </item> <tag><c>catch_exception(Bool)</c></tag> <item> @@ -569,7 +569,7 @@ Hello Number: 3378 <pre> 42> <input>E = ets:new(t, []).</input> -17</pre> +#Ref<0.1662103692.2407923716.214192></pre> <p>Command 42 creates an ETS table.</p> @@ -602,7 +602,7 @@ false</pre> <pre> 47> <input>E = ets:new(t, []).</input> -18 +#Ref<0.1662103692.2407923716.214197> 48> <input>ets:insert({d,1,2}).</input> * exception error: undefined function ets:insert/1</pre> @@ -617,10 +617,23 @@ true</pre> <p>Command 49 successfully inserts the tuple into the ETS table.</p> <pre> -50> <input>halt().</input> +50> <input>ets:insert(#Ref<0.1662103692.2407923716.214197>, {e,3,4}).</input> +true</pre> + + <p>Command 50 inserts another tuple into the ETS table. This time + the first argument is the table identifier itself. The shell can + parse commands with pids (<c><0.60.0></c>), ports + (<c>#Port<0.536></c>), references + (<c>#Ref<0.1662103692.2407792644.214210></c>), and external + functions (<c>#Fun<a.b.1></c>), but the command fails unless + the corresponding pid, port, reference, or function can be created + in the running system.</p> + + <pre> +51> <input>halt().</input> strider 2></pre> - <p>Command 50 exits the Erlang runtime system.</p> + <p>Command 51 exits the Erlang runtime system.</p> </section> <section> @@ -854,7 +867,7 @@ q - quit erlang <c>{history, N}</c>, where <c>N</c> is the current command number. The function is to return a list of characters or an atom. This constraint is because of the Erlang I/O protocol. Unicode characters - beyond code point 255 are allowed in the list. Notice + beyond code point 255 are allowed in the list and the atom. Notice that in restricted mode the call <c>Mod:Func(L)</c> must be allowed or the default shell prompt function is called.</p> </section> diff --git a/lib/stdlib/doc/src/shell_default.xml b/lib/stdlib/doc/src/shell_default.xml index 81c99bce10..75bf89ba8d 100644 --- a/lib/stdlib/doc/src/shell_default.xml +++ b/lib/stdlib/doc/src/shell_default.xml @@ -51,7 +51,7 @@ <p>In command one, module <seealso marker="lists"><c>lists</c></seealso> is called. In command two, no module name is specified. The shell searches module <c>user_default</c> followed by module <c>shell_default</c> for - function <c>foo/1</c>.</p> + function <c>c/1</c>.</p> <p><c>shell_default</c> is intended for "system wide" customizations to the shell. <c>user_default</c> is intended for diff --git a/lib/stdlib/doc/src/stdlib_app.xml b/lib/stdlib/doc/src/stdlib_app.xml index cde73269a8..f857cc394b 100644 --- a/lib/stdlib/doc/src/stdlib_app.xml +++ b/lib/stdlib/doc/src/stdlib_app.xml @@ -31,14 +31,14 @@ <app>STDLIB</app> <appsummary>The STDLIB application.</appsummary> <description> - <p>The <c>STDLIB</c> application is mandatory in the sense that the minimal - system based on Erlang/OTP consists of <c>Kernel</c> and <c>STDLIB</c>. - The <c>STDLIB</c> application contains no services.</p> + <p>The STDLIB application is mandatory in the sense that the minimal + system based on Erlang/OTP consists of Kernel and STDLIB. + The STDLIB application contains no services.</p> </description> <section> <title>Configuration</title> - <p>The following configuration parameters are defined for the <c>STDLIB</c> + <p>The following configuration parameters are defined for the STDLIB application. For more information about configuration parameters, see the <seealso marker="kernel:app"><c>app(4)</c></seealso> module in Kernel.</p> diff --git a/lib/stdlib/doc/src/string.xml b/lib/stdlib/doc/src/string.xml index dddedf1132..9d5edd9ecf 100644 --- a/lib/stdlib/doc/src/string.xml +++ b/lib/stdlib/doc/src/string.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -36,8 +36,617 @@ <modulesummary>String processing functions.</modulesummary> <description> <p>This module provides functions for string processing.</p> + <p>A string in this module is represented by <seealso marker="unicode#type-chardata"> + <c>unicode:chardata()</c></seealso>, that is, a list of codepoints, + binaries with UTF-8-encoded codepoints + (<em>UTF-8 binaries</em>), or a mix of the two.</p> + <code> +"abcd" is a valid string +<<"abcd">> is a valid string +["abcd"] is a valid string +<<"abc..åäö"/utf8>> is a valid string +<<"abc..åäö">> is NOT a valid string, + but a binary with Latin-1-encoded codepoints +[<<"abc">>, "..åäö"] is a valid string +[atom] is NOT a valid string</code> + <p> + This module operates on grapheme clusters. A <em>grapheme cluster</em> + is a user-perceived character, which can be represented by several + codepoints. + </p> + <code> +"å" [229] or [97, 778] +"e̊" [101, 778]</code> + <p> + The string length of "ß↑e̊" is 3, even though it is represented by the + codepoints <c>[223,8593,101,778]</c> or the UTF-8 binary + <c><<195,159,226,134,145,101,204,138>></c>. + </p> + <p> + Grapheme clusters for codepoints of class <c>prepend</c> + and non-modern (or decomposed) Hangul is not handled for performance + reasons in + <seealso marker="#find/3"><c>find/3</c></seealso>, + <seealso marker="#replace/3"><c>replace/3</c></seealso>, + <seealso marker="#split/2"><c>split/2</c></seealso>, + <seealso marker="#lexemes/2"><c>split/2</c></seealso> and + <seealso marker="#trim/3"><c>trim/3</c></seealso>. + </p> + <p> + Splitting and appending strings is to be done on grapheme clusters + borders. + There is no verification that the results of appending strings are + valid or normalized. + </p> + <p> + Most of the functions expect all input to be normalized to one form, + see for example <seealso marker="unicode#characters_to_nfc_list/1"> + <c>unicode:characters_to_nfc_list/1</c></seealso>. + </p> + <p> + Language or locale specific handling of input is not considered + in any function. + </p> + <p> + The functions can crash for non-valid input strings. For example, + the functions expect UTF-8 binaries but not all functions + verify that all binaries are encoded correctly. + </p> + <p> + Unless otherwise specified the return value type is the same as + the input type. That is, binary input returns binary output, + list input returns a list output, and mixed input can return a + mixed output.</p> + <code> +1> string:trim(" sarah "). +"sarah" +2> string:trim(<<" sarah ">>). +<<"sarah">> +3> string:lexemes("foo bar", " "). +["foo","bar"] +4> string:lexemes(<<"foo bar">>, " "). +[<<"foo">>,<<"bar">>]</code> + <p>This module has been reworked in Erlang/OTP 20 to + handle <seealso marker="unicode#type-chardata"> + <c>unicode:chardata()</c></seealso> and operate on grapheme + clusters. The <seealso marker="#oldapi"> <c>old + functions</c></seealso> that only work on Latin-1 lists as input + are still available but should not be + used. They will be deprecated in Erlang/OTP 21. + </p> </description> + <datatypes> + <datatype> + <name name="direction"/> + <name name="grapheme_cluster"/> + <desc> + <p>A user-perceived character, consisting of one or more + codepoints.</p> + </desc> + </datatype> + </datatypes> + + <funcs> + + <func> + <name name="casefold" arity="1"/> + <fsummary>Convert a string to a comparable string.</fsummary> + <desc> + <p> + Converts <c><anno>String</anno></c> to a case-agnostic + comparable string. Function <c>casefold/1</c> is preferred + over <c>lowercase/1</c> when two strings are to be compared + for equality. See also <seealso marker="#equal/4"><c>equal/4</c></seealso>. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>string:casefold("Ω and ẞ SHARP S").</input> +"ω and ss sharp s"</pre> + </desc> + </func> + + <func> + <name name="chomp" arity="1"/> + <fsummary>Remove trailing end of line control characters.</fsummary> + <desc> + <p> + Returns a string where any trailing <c>\n</c> or + <c>\r\n</c> have been removed from <c><anno>String</anno></c>. + </p> + <p><em>Example:</em></p> + <pre> +182> <input>string:chomp(<<"\nHello\n\n">>).</input> +<<"\nHello">> +183> <input>string:chomp("\nHello\r\r\n").</input> +"\nHello\r"</pre> + </desc> + </func> + + <func> + <name name="equal" arity="2"/> + <name name="equal" arity="3"/> + <name name="equal" arity="4"/> + <fsummary>Test string equality.</fsummary> + <desc> + <p> + Returns <c>true</c> if <c><anno>A</anno></c> and + <c><anno>B</anno></c> are equal, otherwise <c>false</c>. + </p> + <p> + If <c><anno>IgnoreCase</anno></c> is <c>true</c> + the function does <seealso marker="#casefold/1"> + <c>casefold</c>ing</seealso> on the fly before the equality test. + </p> + <p>If <c><anno>Norm</anno></c> is not <c>none</c> + the function applies normalization on the fly before the equality test. + There are four available normalization forms: + <seealso marker="unicode#characters_to_nfc_list/1"> <c>nfc</c></seealso>, + <seealso marker="unicode#characters_to_nfd_list/1"> <c>nfd</c></seealso>, + <seealso marker="unicode#characters_to_nfkc_list/1"> <c>nfkc</c></seealso>, and + <seealso marker="unicode#characters_to_nfkd_list/1"> <c>nfkd</c></seealso>. + </p> + <p>By default, + <c><anno>IgnoreCase</anno></c> is <c>false</c> and + <c><anno>Norm</anno></c> is <c>none</c>.</p> + <p><em>Example:</em></p> + <pre> +1> <input>string:equal("åäö", <<"åäö"/utf8>>).</input> +true +2> <input>string:equal("åäö", unicode:characters_to_nfd_binary("åäö")).</input> +false +3> <input>string:equal("åäö", unicode:characters_to_nfd_binary("ÅÄÖ"), true, nfc).</input> +true</pre> + </desc> + </func> + + <func> + <name name="find" arity="2"/> + <name name="find" arity="3"/> + <fsummary>Find start of substring.</fsummary> + <desc> + <p> + Removes anything before <c><anno>SearchPattern</anno></c> in <c><anno>String</anno></c> + and returns the remainder of the string or <c>nomatch</c> if <c><anno>SearchPattern</anno></c> is not + found. + <c><anno>Dir</anno></c>, which can be <c>leading</c> or + <c>trailing</c>, indicates from which direction characters + are to be searched. + </p> + <p> + By default, <c><anno>Dir</anno></c> is <c>leading</c>. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>string:find("ab..cd..ef", ".").</input> +"..cd..ef" +2> <input>string:find(<<"ab..cd..ef">>, "..", trailing).</input> +<<"..ef">> +3> <input>string:find(<<"ab..cd..ef">>, "x", leading).</input> +nomatch +4> <input>string:find("ab..cd..ef", "x", trailing).</input> +nomatch</pre> + </desc> + </func> + + <func> + <name name="is_empty" arity="1"/> + <fsummary>Check if the string is empty.</fsummary> + <desc> + <p>Returns <c>true</c> if <c><anno>String</anno></c> is the + empty string, otherwise <c>false</c>.</p> + <p><em>Example:</em></p> + <pre> +1> <input>string:is_empty("foo").</input> +false +2> <input>string:is_empty(["",<<>>]).</input> +true</pre> + </desc> + </func> + + <func> + <name name="length" arity="1"/> + <fsummary>Calculate length of the string.</fsummary> + <desc> + <p> + Returns the number of grapheme clusters in <c><anno>String</anno></c>. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>string:length("ß↑e̊").</input> +3 +2> <input>string:length(<<195,159,226,134,145,101,204,138>>).</input> +3</pre> + </desc> + </func> + + <func> + <name name="lexemes" arity="2"/> + <fsummary>Split string into lexemes.</fsummary> + <desc> + <p> + Returns a list of lexemes in <c><anno>String</anno></c>, separated + by the grapheme clusters in <c><anno>SeparatorList</anno></c>. + </p> + <p> + Notice that, as shown in this example, two or more + adjacent separator graphemes clusters in <c><anno>String</anno></c> + are treated as one. That is, there are no empty + strings in the resulting list of lexemes. + See also <seealso marker="#split/3"><c>split/3</c></seealso> which returns + empty strings. + </p> + <p>Notice that <c>[$\r,$\n]</c> is one grapheme cluster.</p> + <p><em>Example:</em></p> + <pre> +1> <input>string:lexemes("abc de̊fxxghix jkl\r\nfoo", "x e" ++ [[$\r,$\n]]).</input> +["abc","de̊f","ghi","jkl","foo"] +2> <input>string:lexemes(<<"abc de̊fxxghix jkl\r\nfoo"/utf8>>, "x e" ++ [$\r,$\n]).</input> +[<<"abc">>,<<"de̊f"/utf8>>,<<"ghi">>,<<"jkl\r\nfoo">>]</pre> + </desc> + </func> + + <func> + <name name="lowercase" arity="1"/> + <fsummary>Convert a string to lowercase</fsummary> + <desc> + <p> + Converts <c><anno>String</anno></c> to lowercase. + </p> + <p> + Notice that function <seealso marker="#casefold/1"><c>casefold/1</c></seealso> + should be used when converting a string to + be tested for equality. + </p> + <p><em>Example:</em></p> + <pre> +2> <input>string:lowercase(string:uppercase("Michał")).</input> +"michał"</pre> + </desc> + </func> + + <func> + <name name="next_codepoint" arity="1"/> + <fsummary>Pick the first codepoint.</fsummary> + <desc> + <p> + Returns the first codepoint in <c><anno>String</anno></c> + and the rest of <c><anno>String</anno></c> in the tail. Returns + an empty list if <c><anno>String</anno></c> is empty or an + <c>{error, String}</c> tuple if the next byte is invalid. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>string:next_codepoint(unicode:characters_to_binary("e̊fg")).</input> +[101|<<"̊fg"/utf8>>]</pre> + </desc> + </func> + + <func> + <name name="next_grapheme" arity="1"/> + <fsummary>Pick the first grapheme cluster.</fsummary> + <desc> + <p> + Returns the first grapheme cluster in <c><anno>String</anno></c> + and the rest of <c><anno>String</anno></c> in the tail. Returns + an empty list if <c><anno>String</anno></c> is empty or an + <c>{error, String}</c> tuple if the next byte is invalid. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>string:next_grapheme(unicode:characters_to_binary("e̊fg")).</input> +["e̊"|<<"fg">>]</pre> + </desc> + </func> + + <func> + <name name="nth_lexeme" arity="3"/> + <fsummary>Pick the nth lexeme.</fsummary> + <desc> + <p>Returns lexeme number <c><anno>N</anno></c> in + <c><anno>String</anno></c>, where lexemes are separated by + the grapheme clusters in <c><anno>SeparatorList</anno></c>. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>string:nth_lexeme("abc.de̊f.ghiejkl", 3, ".e").</input> +"ghi"</pre> + </desc> + </func> + + <func> + <name name="pad" arity="2"/> + <name name="pad" arity="3"/> + <name name="pad" arity="4"/> + <fsummary>Pad a string to given length.</fsummary> + <desc> + <p> + Pads <c><anno>String</anno></c> to <c><anno>Length</anno></c> with + grapheme cluster <c><anno>Char</anno></c>. + <c><anno>Dir</anno></c>, which can be <c>leading</c>, <c>trailing</c>, + or <c>both</c>, indicates where the padding should be added. + </p> + <p>By default, <c><anno>Char</anno></c> is <c>$\s</c> and + <c><anno>Dir</anno></c> is <c>trailing</c>. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>string:pad(<<"He̊llö"/utf8>>, 8).</input> +[<<72,101,204,138,108,108,195,182>>,32,32,32] +2> <input>io:format("'~ts'~n",[string:pad("He̊llö", 8, leading)]).</input> +' He̊llö' +3> <input>io:format("'~ts'~n",[string:pad("He̊llö", 8, both)]).</input> +' He̊llö '</pre> + </desc> + </func> + + <func> + <name name="prefix" arity="2"/> + <fsummary>Remove prefix from string.</fsummary> + <desc> + <p> + If <c><anno>Prefix</anno></c> is the prefix of + <c><anno>String</anno></c>, removes it and returns the + remainder of <c><anno>String</anno></c>, otherwise returns + <c>nomatch</c>. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>string:prefix(<<"prefix of string">>, "pre").</input> +<<"fix of string">> +2> <input>string:prefix("pre", "prefix").</input> +nomatch</pre> + </desc> + </func> + + <func> + <name name="replace" arity="3"/> + <name name="replace" arity="4"/> + <fsummary>Replace a pattern in string.</fsummary> + <desc> + <p> + Replaces <c><anno>SearchPattern</anno></c> in <c><anno>String</anno></c> + with <c><anno>Replacement</anno></c>. + <c><anno>Where</anno></c>, default <c>leading</c>, indicates whether + the <c>leading</c>, the <c>trailing</c> or <c>all</c> encounters of + <c><anno>SearchPattern</anno></c> are to be replaced. + </p> + <p>Can be implemented as:</p> + <pre>lists:join(Replacement, split(String, SearchPattern, Where)).</pre> + <p><em>Example:</em></p> + <pre> +1> <input>string:replace(<<"ab..cd..ef">>, "..", "*").</input> +[<<"ab">>,"*",<<"cd..ef">>] +2> <input>string:replace(<<"ab..cd..ef">>, "..", "*", all).</input> +[<<"ab">>,"*",<<"cd">>,"*",<<"ef">>]</pre> + </desc> + </func> + + <func> + <name name="reverse" arity="1"/> + <fsummary>Reverses a string</fsummary> + <desc> + <p> + Returns the reverse list of the grapheme clusters in <c><anno>String</anno></c>. + </p> + <p><em>Example:</em></p> + <pre> +1> Reverse = <input>string:reverse(unicode:characters_to_nfd_binary("ÅÄÖ")).</input> +[[79,776],[65,776],[65,778]] +2> <input>io:format("~ts~n",[Reverse]).</input> +ÖÄÅ</pre> + </desc> + </func> + + <func> + <name name="slice" arity="2"/> + <name name="slice" arity="3"/> + <fsummary>Extract a part of string</fsummary> + <desc> + <p>Returns a substring of <c><anno>String</anno></c> of + at most <c><anno>Length</anno></c> grapheme clusters, starting at position + <c><anno>Start</anno></c>.</p> + <p>By default, <c><anno>Length</anno></c> is <c>infinity</c>.</p> + <p><em>Example:</em></p> + <pre> +1> <input>string:slice(<<"He̊llö Wörld"/utf8>>, 4).</input> +<<"ö Wörld"/utf8>> +2> <input>string:slice(["He̊llö ", <<"Wörld"/utf8>>], 4,4).</input> +"ö Wö" +3> <input>string:slice(["He̊llö ", <<"Wörld"/utf8>>], 4,50).</input> +"ö Wörld"</pre> + </desc> + </func> + + <func> + <name name="split" arity="2"/> + <name name="split" arity="3"/> + <fsummary>Split a string into substrings.</fsummary> + <desc> + <p> + Splits <c><anno>String</anno></c> where <c><anno>SearchPattern</anno></c> + is encountered and return the remaining parts. + <c><anno>Where</anno></c>, default <c>leading</c>, indicates whether + the <c>leading</c>, the <c>trailing</c> or <c>all</c> encounters of + <c><anno>SearchPattern</anno></c> will split <c><anno>String</anno></c>. + </p> + <p><em>Example:</em></p> + <pre> +0> <input>string:split("ab..bc..cd", "..").</input> +["ab","bc..cd"] +1> <input>string:split(<<"ab..bc..cd">>, "..", trailing).</input> +[<<"ab..bc">>,<<"cd">>] +2> <input>string:split(<<"ab..bc....cd">>, "..", all).</input> +[<<"ab">>,<<"bc">>,<<>>,<<"cd">>]</pre> + </desc> + </func> + + <func> + <name name="take" arity="2"/> + <name name="take" arity="3"/> + <name name="take" arity="4"/> + <fsummary>Take leading or trailing parts.</fsummary> + <desc> + <p>Takes characters from <c><anno>String</anno></c> as long as + the characters are members of set <c><anno>Characters</anno></c> + or the complement of set <c><anno>Characters</anno></c>. + <c><anno>Dir</anno></c>, + which can be <c>leading</c> or <c>trailing</c>, indicates from + which direction characters are to be taken. + </p> + <p><em>Example:</em></p> + <pre> +5> <input>string:take("abc0z123", lists:seq($a,$z)).</input> +{"abc","0z123"} +6> <input>string:take(<<"abc0z123">>, lists:seq($0,$9), true, leading).</input> +{<<"abc">>,<<"0z123">>} +7> <input>string:take("abc0z123", lists:seq($0,$9), false, trailing).</input> +{"abc0z","123"} +8> <input>string:take(<<"abc0z123">>, lists:seq($a,$z), true, trailing).</input> +{<<"abc0z">>,<<"123">>}</pre> + </desc> + </func> + + <func> + <name name="titlecase" arity="1"/> + <fsummary>Convert a string to titlecase.</fsummary> + <desc> + <p> + Converts <c><anno>String</anno></c> to titlecase. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>string:titlecase("ß is a SHARP s").</input> +"Ss is a SHARP s"</pre> + </desc> + </func> + + <func> + <name name="to_float" arity="1"/> + <fsummary>Return a float whose text representation is the integers + (ASCII values) of a string.</fsummary> + <desc> + <p>Argument <c><anno>String</anno></c> is expected to start with a + valid text represented float (the digits are ASCII values). + Remaining characters in the string after the float are returned in + <c><anno>Rest</anno></c>.</p> + <p><em>Example:</em></p> + <pre> +> <input>{F1,Fs} = string:to_float("1.0-1.0e-1"),</input> +> <input>{F2,[]} = string:to_float(Fs),</input> +> <input>F1+F2.</input> +0.9 +> <input>string:to_float("3/2=1.5").</input> +{error,no_float} +> <input>string:to_float("-1.5eX").</input> +{-1.5,"eX"}</pre> + </desc> + </func> + + <func> + <name name="to_integer" arity="1"/> + <fsummary>Return an integer whose text representation is the integers + (ASCII values) of a string.</fsummary> + <desc> + <p>Argument <c><anno>String</anno></c> is expected to start with a + valid text represented integer (the digits are ASCII values). + Remaining characters in the string after the integer are returned in + <c><anno>Rest</anno></c>.</p> + <p><em>Example:</em></p> + <pre> +> <input>{I1,Is} = string:to_integer("33+22"),</input> +> <input>{I2,[]} = string:to_integer(Is),</input> +> <input>I1-I2.</input> +11 +> <input>string:to_integer("0.5").</input> +{0,".5"} +> <input>string:to_integer("x=2").</input> +{error,no_integer}</pre> + </desc> + </func> + + <func> + <name name="to_graphemes" arity="1"/> + <fsummary>Convert a string to a list of grapheme clusters.</fsummary> + <desc> + <p> + Converts <c><anno>String</anno></c> to a list of grapheme clusters. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>string:to_graphemes("ß↑e̊").</input> +[223,8593,[101,778]] +2> <input>string:to_graphemes(<<"ß↑e̊"/utf8>>).</input> +[223,8593,[101,778]]</pre> + </desc> + </func> + + <func> + <name name="trim" arity="1"/> + <name name="trim" arity="2"/> + <name name="trim" arity="3"/> + <fsummary>Trim leading or trailing, or both, characters.</fsummary> + <desc> + <p> + Returns a string, where leading or trailing, or both, + <c><anno>Characters</anno></c> have been removed. + <c><anno>Dir</anno></c> which can be <c>leading</c>, <c>trailing</c>, + or <c>both</c>, indicates from which direction characters + are to be removed. + </p> + <p> Default <c><anno>Characters</anno></c> are the set of + nonbreakable whitespace codepoints, defined as + Pattern_White_Space in + <url href="http://unicode.org/reports/tr31/">Unicode Standard Annex #31</url>. + <c>By default, <anno>Dir</anno></c> is <c>both</c>. + </p> + <p> + Notice that <c>[$\r,$\n]</c> is one grapheme cluster according + to the Unicode Standard. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>string:trim("\t Hello \n").</input> +"Hello" +2> <input>string:trim(<<"\t Hello \n">>, leading).</input> +<<"Hello \n">> +3> <input>string:trim(<<".Hello.\n">>, trailing, "\n.").</input> +<<".Hello">></pre> + </desc> + </func> + + <func> + <name name="uppercase" arity="1"/> + <fsummary>Convert a string to uppercase.</fsummary> + <desc> + <p> + Converts <c><anno>String</anno></c> to uppercase. + </p> + <p>See also <seealso marker="#titlecase/1"><c>titlecase/1</c></seealso>.</p> + <p><em>Example:</em></p> + <pre> +1> <input>string:uppercase("Michał").</input> +"MICHAŁ"</pre> + </desc> + </func> + + </funcs> + + <section> + <marker id="oldapi"/> + <title>Obsolete API functions</title> + <p>Here follows the function of the old API. + These functions only work on a list of Latin-1 characters. + </p> + <note><p> + The functions are kept for backward compatibility, but are + not recommended. + They will be deprecated in Erlang/OTP 21. + </p> + <p>Any undocumented functions in <c>string</c> are not to be used.</p> + </note> + </section> + <funcs> <func> <name name="centre" arity="2"/> @@ -47,17 +656,24 @@ <p>Returns a string, where <c><anno>String</anno></c> is centered in the string and surrounded by blanks or <c><anno>Character</anno></c>. The resulting string has length <c><anno>Number</anno></c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#pad/3"><c>pad/3</c></seealso>. + </p> </desc> </func> <func> <name name="chars" arity="2"/> <name name="chars" arity="3"/> - <fsummary>Returns a string consisting of numbers of characters.</fsummary> + <fsummary>Return a string consisting of numbers of characters.</fsummary> <desc> <p>Returns a string consisting of <c><anno>Number</anno></c> characters <c><anno>Character</anno></c>. Optionally, the string can end with string <c><anno>Tail</anno></c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="lists#duplicate/2"><c>lists:duplicate/2</c></seealso>.</p> </desc> </func> @@ -69,6 +685,9 @@ <p>Returns the index of the first occurrence of <c><anno>Character</anno></c> in <c><anno>String</anno></c>. Returns <c>0</c> if <c><anno>Character</anno></c> does not occur.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#find/2"><c>find/2</c></seealso>.</p> </desc> </func> @@ -79,6 +698,16 @@ <p>Concatenates <c><anno>String1</anno></c> and <c><anno>String2</anno></c> to form a new string <c><anno>String3</anno></c>, which is returned.</p> + <p> + This function is <seealso marker="#oldapi">obsolete</seealso>. + Use <c>[<anno>String1</anno>, <anno>String2</anno>]</c> as + <c>Data</c> argument, and call + <seealso marker="unicode#characters_to_list/2"> + <c>unicode:characters_to_list/2</c></seealso> or + <seealso marker="unicode#characters_to_binary/2"> + <c>unicode:characters_to_binary/2</c></seealso> + to flatten the output. + </p> </desc> </func> @@ -88,6 +717,9 @@ <desc> <p>Returns a string containing <c><anno>String</anno></c> repeated <c><anno>Number</anno></c> times.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="lists#duplicate/2"><c>lists:duplicate/2</c></seealso>.</p> </desc> </func> @@ -98,6 +730,9 @@ <p>Returns the length of the maximum initial segment of <c><anno>String</anno></c>, which consists entirely of characters not from <c><anno>Chars</anno></c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#take/3"><c>take/3</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> > string:cspan("\t abcdef", " \t"). @@ -106,20 +741,14 @@ </func> <func> - <name name="equal" arity="2"/> - <fsummary>Test string equality.</fsummary> - <desc> - <p>Returns <c>true</c> if <c><anno>String1</anno></c> and - <c><anno>String2</anno></c> are equal, otherwise <c>false</c>.</p> - </desc> - </func> - - <func> <name name="join" arity="2"/> <fsummary>Join a list of strings with separator.</fsummary> <desc> <p>Returns a string with the elements of <c><anno>StringList</anno></c> separated by the string in <c><anno>Separator</anno></c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="lists#join/2"><c>lists:join/2</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> > join(["one", "two", "three"], ", "). @@ -137,6 +766,10 @@ fixed. If <c>length(<anno>String</anno>)</c> < <c><anno>Number</anno></c>, then <c><anno>String</anno></c> is padded with blanks or <c><anno>Character</anno></c>s.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#pad/2"><c>pad/2</c></seealso> or + <seealso marker="#pad/3"><c>pad/3</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> > string:left("Hello",10,$.). @@ -149,6 +782,9 @@ <fsummary>Return the length of a string.</fsummary> <desc> <p>Returns the number of characters in <c><anno>String</anno></c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#length/1"><c>length/1</c></seealso>.</p> </desc> </func> @@ -160,6 +796,9 @@ <p>Returns the index of the last occurrence of <c><anno>Character</anno></c> in <c><anno>String</anno></c>. Returns <c>0</c> if <c><anno>Character</anno></c> does not occur.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#find/3"><c>find/3</c></seealso>.</p> </desc> </func> @@ -173,6 +812,9 @@ fixed. If the length of <c>(<anno>String</anno>)</c> < <c><anno>Number</anno></c>, then <c><anno>String</anno></c> is padded with blanks or <c><anno>Character</anno></c>s.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#pad/3"><c>pad/3</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> > string:right("Hello", 10, $.). @@ -188,6 +830,9 @@ <c><anno>SubString</anno></c> begins in <c><anno>String</anno></c>. Returns <c>0</c> if <c><anno>SubString</anno></c> does not exist in <c><anno>String</anno></c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#find/3"><c>find/3</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> > string:rstr(" Hello Hello World World ", "Hello World"). @@ -202,6 +847,9 @@ <p>Returns the length of the maximum initial segment of <c><anno>String</anno></c>, which consists entirely of characters from <c><anno>Chars</anno></c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#take/2"><c>take/2</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> > string:span("\t abcdef", " \t"). @@ -217,6 +865,9 @@ <c><anno>SubString</anno></c> begins in <c><anno>String</anno></c>. Returns <c>0</c> if <c><anno>SubString</anno></c> does not exist in <c><anno>String</anno></c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#find/2"><c>find/2</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> > string:str(" Hello Hello World World ", "Hello World"). @@ -230,12 +881,15 @@ <name name="strip" arity="3"/> <fsummary>Strip leading or trailing characters.</fsummary> <desc> - <p>Returns a string, where leading and/or trailing blanks or a + <p>Returns a string, where leading or trailing, or both, blanks or a number of <c><anno>Character</anno></c> have been removed. <c><anno>Direction</anno></c>, which can be <c>left</c>, <c>right</c>, or <c>both</c>, indicates from which direction blanks are to be removed. <c>strip/1</c> is equivalent to <c>strip(String, both)</c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#trim/3"><c>trim/3</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> > string:strip("...Hello.....", both, $.). @@ -251,6 +905,9 @@ <p>Returns a substring of <c><anno>String</anno></c>, starting at position <c><anno>Start</anno></c> to the end of the string, or to and including position <c><anno>Stop</anno></c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#slice/3"><c>slice/3</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> sub_string("Hello World", 4, 8). @@ -266,6 +923,9 @@ sub_string("Hello World", 4, 8). <p>Returns a substring of <c><anno>String</anno></c>, starting at position <c><anno>Start</anno></c>, and ending at the end of the string or at length <c><anno>Length</anno></c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#slice/3"><c>slice/3</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> > substr("Hello World", 4, 5). @@ -281,6 +941,9 @@ sub_string("Hello World", 4, 8). <p>Returns the word in position <c><anno>Number</anno></c> of <c><anno>String</anno></c>. Words are separated by blanks or <c><anno>Character</anno></c>s.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#nth_lexeme/3"><c>nth_lexeme/3</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> > string:sub_word(" Hello old boy !",3,$o). @@ -289,50 +952,6 @@ sub_string("Hello World", 4, 8). </func> <func> - <name name="to_float" arity="1"/> - <fsummary>Returns a float whose text representation is the integers - (ASCII values) in a string.</fsummary> - <desc> - <p>Argument <c><anno>String</anno></c> is expected to start with a - valid text represented float (the digits are ASCII values). - Remaining characters in the string after the float are returned in - <c><anno>Rest</anno></c>.</p> - <p><em>Example:</em></p> - <code type="none"> -> {F1,Fs} = string:to_float("1.0-1.0e-1"), -> {F2,[]} = string:to_float(Fs), -> F1+F2. -0.9 -> string:to_float("3/2=1.5"). -{error,no_float} -> string:to_float("-1.5eX"). -{-1.5,"eX"}</code> - </desc> - </func> - - <func> - <name name="to_integer" arity="1"/> - <fsummary>Returns an integer whose text representation is the integers - (ASCII values) in a string.</fsummary> - <desc> - <p>Argument <c><anno>String</anno></c> is expected to start with a - valid text represented integer (the digits are ASCII values). - Remaining characters in the string after the integer are returned in - <c><anno>Rest</anno></c>.</p> - <p><em>Example:</em></p> - <code type="none"> -> {I1,Is} = string:to_integer("33+22"), -> {I2,[]} = string:to_integer(Is), -> I1-I2. -11 -> string:to_integer("0.5"). -{0,".5"} -> string:to_integer("x=2"). -{error,no_integer}</code> - </desc> - </func> - - <func> <name name="to_lower" arity="1" clause_i="1"/> <name name="to_lower" arity="1" clause_i="2"/> <name name="to_upper" arity="1" clause_i="1"/> @@ -346,6 +965,11 @@ sub_string("Hello World", 4, 8). <p>The specified string or character is case-converted. Notice that the supported character set is ISO/IEC 8859-1 (also called Latin 1); all values outside this set are unchanged</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso> use + <seealso marker="#lowercase/1"><c>lowercase/1</c></seealso>, + <seealso marker="#uppercase/1"><c>uppercase/1</c></seealso>, + <seealso marker="#titlecase/1"><c>titlecase/1</c></seealso> or + <seealso marker="#casefold/1"><c>casefold/1</c></seealso>.</p> </desc> </func> @@ -363,6 +987,9 @@ sub_string("Hello World", 4, 8). adjacent separator characters in <c><anno>String</anno></c> are treated as one. That is, there are no empty strings in the resulting list of tokens.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#lexemes/2"><c>lexemes/2</c></seealso>.</p> </desc> </func> @@ -373,6 +1000,9 @@ sub_string("Hello World", 4, 8). <desc> <p>Returns the number of words in <c><anno>String</anno></c>, separated by blanks or <c><anno>Character</anno></c>.</p> + <p>This function is <seealso marker="#oldapi">obsolete</seealso>. + Use + <seealso marker="#lexemes/2"><c>lexemes/2</c></seealso>.</p> <p><em>Example:</em></p> <code type="none"> > words(" Hello old boy!", $o). @@ -387,10 +1017,7 @@ sub_string("Hello World", 4, 8). other. The reason is that this string package is the combination of two earlier packages and all functions of both packages have been retained.</p> - - <note> - <p>Any undocumented functions in <c>string</c> are not to be used.</p> - </note> </section> + </erlref> diff --git a/lib/stdlib/doc/src/supervisor.xml b/lib/stdlib/doc/src/supervisor.xml index 294196f746..6d5065ca02 100644 --- a/lib/stdlib/doc/src/supervisor.xml +++ b/lib/stdlib/doc/src/supervisor.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -36,7 +36,6 @@ process can either be another supervisor or a worker process. Worker processes are normally implemented using one of the <seealso marker="gen_event"><c>gen_event</c></seealso>, - <seealso marker="gen_fsm"><c>gen_fsm</c></seealso>, <seealso marker="gen_server"><c>gen_server</c></seealso>, or <seealso marker="gen_statem"><c>gen_statem</c></seealso> behaviors. A supervisor implemented using this module has @@ -133,8 +132,10 @@ sup_flags() = #{strategy => strategy(), % optional map. Assuming the values <c>MaxR</c> for <c>intensity</c> and <c>MaxT</c> for <c>period</c>, then, if more than <c>MaxR</c> restarts occur within <c>MaxT</c> seconds, the supervisor - terminates all child processes and then itself. <c>intensity</c> - defaults to <c>1</c> and <c>period</c> defaults to <c>5</c>.</p> + terminates all child processes and then itself. The termination + reason for the supervisor itself in that case will be <c>shutdown</c>. + <c>intensity</c> defaults to <c>1</c> and <c>period</c> defaults to + <c>5</c>.</p> <marker id="child_spec"/> <p>The type definition of a child specification is as follows:</p> @@ -235,8 +236,8 @@ child_spec() = #{id => child_id(), % mandatory <p><c>modules</c> is used by the release handler during code replacement to determine which processes are using a certain module. As a rule of thumb, if the child process is a - <c>supervisor</c>, <c>gen_server</c>, - <c>gen_statem</c>, or <c>gen_fsm</c>, + <c>supervisor</c>, <c>gen_server</c> or, + <c>gen_statem</c>, this is to be a list with one element <c>[Module]</c>, where <c>Module</c> is the callback module. If the child process is an event manager (<c>gen_event</c>) with a @@ -704,7 +705,6 @@ child_spec() = #{id => child_id(), % mandatory <section> <title>See Also</title> <p><seealso marker="gen_event"><c>gen_event(3)</c></seealso>, - <seealso marker="gen_fsm"><c>gen_fsm(3)</c></seealso>, <seealso marker="gen_statem"><c>gen_statem(3)</c></seealso>, <seealso marker="gen_server"><c>gen_server(3)</c></seealso>, <seealso marker="sys"><c>sys(3)</c></seealso></p> diff --git a/lib/stdlib/doc/src/sys.xml b/lib/stdlib/doc/src/sys.xml index 1120b926d5..64d8789016 100644 --- a/lib/stdlib/doc/src/sys.xml +++ b/lib/stdlib/doc/src/sys.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2014</year> + <year>1996</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -83,8 +83,8 @@ <p>If the modules used to implement the process change dynamically during runtime, the process must understand one more message. An example is the <seealso marker="gen_event"><c>gen_event</c></seealso> - processes. The message is <c>{get_modules, From}</c>. - The reply to this message is <c>From ! {modules, Modules}</c>, where + processes. The message is <c>{_Label, {From, Ref}, get_modules}</c>. + The reply to this message is <c>From ! {Ref, Modules}</c>, where <c>Modules</c> is a list of the currently active modules in the process.</p> <p>This message is used by the release handler to find which @@ -168,12 +168,6 @@ </item> <item> <p>For a - <seealso marker="gen_fsm"><c>gen_fsm</c></seealso> - process, <c><anno>State</anno></c> is the tuple - <c>{CurrentStateName, CurrentStateData}</c>.</p> - </item> - <item> - <p>For a <seealso marker="gen_statem"><c>gen_statem</c></seealso> process, <c><anno>State</anno></c> is the tuple <c>{CurrentState,CurrentData}</c>.</p> @@ -222,7 +216,7 @@ <p>Function <c>system_get_state/1</c> is primarily useful for user-defined behaviors and modules that implement OTP <seealso marker="#special_process">special processes</seealso>. - The <c>gen_server</c>, <c>gen_fsm</c>, + The <c>gen_server</c>, <c>gen_statem</c>, and <c>gen_event</c> OTP behavior modules export this function, so callback modules for those behaviors need not to supply their own.</p> @@ -246,11 +240,6 @@ process returns the state of the callback module.</p> </item> <item> - <p>A <seealso marker="gen_fsm"><c>gen_fsm</c></seealso> - process returns information, such as its current - state name and state data.</p> - </item> - <item> <p>A <seealso marker="gen_statem"><c>gen_statem</c></seealso> process returns information, such as its current state name and state data.</p> @@ -262,14 +251,12 @@ </item> </list> <p>Callback modules for <c>gen_server</c>, - <c>gen_fsm</c>, <c>gen_statem</c>, and <c>gen_event</c> + <c>gen_statem</c>, and <c>gen_event</c> can also change the value of <c><anno>Misc</anno></c> by exporting a function <c>format_status/2</c>, which contributes module-specific information. For details, see <seealso marker="gen_server#Module:format_status/2"> <c>gen_server:format_status/2</c></seealso>, - <seealso marker="gen_fsm#Module:format_status/2"> - <c>gen_fsm:format_status/2</c></seealso>, <seealso marker="gen_statem#Module:format_status/2"> <c>gen_statem:format_status/2</c></seealso>, and <seealso marker="gen_event#Module:format_status/2"> @@ -321,7 +308,7 @@ format to the file. The events are formatted with a function that is defined by the process that generated the event (with a call to <seealso marker="#handle_debug/4"><c>handle_debug/4</c></seealso>). - </p> + The file is opened with encoding UTF-8.</p> </desc> </func> @@ -373,13 +360,6 @@ is a new instance of that state.</p> </item> <item> - <p>For a <seealso marker="gen_fsm"><c>gen_fsm</c></seealso> process, - <c><anno>State</anno></c> is the tuple <c>{CurrentStateName, - CurrentStateData}</c>, and <c><anno>NewState</anno></c> is a - similar tuple, which can contain - a new state name, new state data, or both.</p> - </item> - <item> <p>For a <seealso marker="gen_statem"><c>gen_statem</c></seealso> process, <c><anno>State</anno></c> is the tuple <c>{CurrentState,CurrentData}</c>, @@ -422,7 +402,7 @@ return its <c><anno>State</anno></c> argument.</p> <p>If a <c><anno>StateFun</anno></c> function crashes or throws an exception, the original state of the process is unchanged for - <c>gen_server</c>, <c>gen_fsm</c>, and <c>gen_statem</c> processes. + <c>gen_server</c>, and <c>gen_statem</c> processes. For <c>gen_event</c> processes, a crashing or failing <c><anno>StateFun</anno></c> function means that only the state of the particular event handler it was @@ -462,7 +442,7 @@ user-defined behaviors and modules that implement OTP <seealso marker="#special_process">special processes</seealso>. The OTP behavior modules <c>gen_server</c>, - <c>gen_fsm</c>, <c>gen_statem</c>, and <c>gen_event</c> + <c>gen_statem</c>, and <c>gen_event</c> export this function, so callback modules for those behaviors need not to supply their own.</p> </desc> diff --git a/lib/stdlib/doc/src/timer.xml b/lib/stdlib/doc/src/timer.xml index 8f2ce36b06..fcaccdb2cb 100644 --- a/lib/stdlib/doc/src/timer.xml +++ b/lib/stdlib/doc/src/timer.xml @@ -253,7 +253,7 @@ is needed. This is useful during development, but in a target system the server is to be started explicitly. Use configuration parameters for - <seealso marker="kernel:index"><c>Kernel</c></seealso> for this.</p> + <seealso marker="kernel:index">Kernel</seealso> for this.</p> </desc> </func> diff --git a/lib/stdlib/doc/src/unicode.xml b/lib/stdlib/doc/src/unicode.xml index 93d0d37456..e86f45431f 100644 --- a/lib/stdlib/doc/src/unicode.xml +++ b/lib/stdlib/doc/src/unicode.xml @@ -5,7 +5,7 @@ <header> <copyright> <year>1996</year> - <year>2016</year> + <year>2017</year> <holder>Ericsson AB, All Rights Reserved</holder> </copyright> <legalnotice> @@ -50,8 +50,35 @@ external entities where this is required. When working inside the Erlang/OTP environment, it is recommended to keep binaries in UTF-8 when representing Unicode characters. ISO Latin-1 encoding is supported both - for backward compatibility and for communication - with external entities not supporting Unicode character sets.</p> + for backward compatibility and for communication + with external entities not supporting Unicode character sets.</p> + <p>Programs should always operate on a normalized form and compare + canonical-equivalent Unicode characters as equal. All characters + should thus be normalized to one form once on the system borders. + One of the following functions can convert characters to their + normalized forms <seealso marker="#characters_to_nfc_list/1"> + <c>characters_to_nfc_list/1</c></seealso>, + <seealso marker="#characters_to_nfc_binary/1"> + <c>characters_to_nfc_binary/1</c></seealso>, + <seealso marker="#characters_to_nfd_list/1"> + <c>characters_to_nfd_list/1</c></seealso> or + <seealso marker="#characters_to_nfd_binary/1"> + <c>characters_to_nfd_binary/1</c></seealso>. + For general text + <seealso marker="#characters_to_nfc_list/1"> + <c>characters_to_nfc_list/1</c></seealso> or + <seealso marker="#characters_to_nfc_binary/1"> + <c>characters_to_nfc_binary/1</c></seealso> is preferred, and + for identifiers one of the compatibility normalization + functions, such as + <seealso marker="#characters_to_nfkc_list/1"> + <c>characters_to_nfkc_list/1</c></seealso>, + is preferred for security reasons. + The normalization functions where introduced in OTP 20. + Additional information on normalization can be found in the + <url href="http://unicode.org/faq/normalization.html">Unicode FAQ</url>. + </p> + </description> <datatypes> @@ -335,6 +362,154 @@ decode_data(Data) -> </func> <func> + <name name="characters_to_nfc_list" arity="1"/> + <fsummary>Normalize characters to a list of canonical equivalent + composed Unicode characters.</fsummary> + <desc> + <p>Converts a possibly deep list of characters and binaries + into a Normalized Form of canonical equivalent Composed + characters according to the Unicode standard.</p> + <p>Any binaries in the input must be encoded with utf8 + encoding. + </p> + <p>The result is a list of characters.</p> + <code> +3> unicode:characters_to_nfc_list([<<"abc..a">>,[778],$a,[776],$o,[776]]). +"abc..åäö" +</code> + </desc> + </func> + + <func> + <name name="characters_to_nfc_binary" arity="1"/> + <fsummary>Normalize characters to a utf8 binary of canonical equivalent + composed Unicode characters.</fsummary> + <desc> + <p>Converts a possibly deep list of characters and binaries + into a Normalized Form of canonical equivalent Composed + characters according to the Unicode standard.</p> + <p>Any binaries in the input must be encoded with utf8 + encoding.</p> + <p>The result is an utf8 encoded binary.</p> + <code> +4> unicode:characters_to_nfc_binary([<<"abc..a">>,[778],$a,[776],$o,[776]]). +<<"abc..åäö"/utf8>> +</code> + </desc> + </func> + + <func> + <name name="characters_to_nfd_list" arity="1"/> + <fsummary>Normalize characters to a list of canonical equivalent + decomposed Unicode characters.</fsummary> + <desc> + <p>Converts a possibly deep list of characters and binaries + into a Normalized Form of canonical equivalent Decomposed + characters according to the Unicode standard.</p> + <p>Any binaries in the input must be encoded with utf8 + encoding. + </p> + <p>The result is a list of characters.</p> + <code> +1> unicode:characters_to_nfd_list("abc..åäö"). +[97,98,99,46,46,97,778,97,776,111,776] +</code> + </desc> + </func> + + <func> + <name name="characters_to_nfd_binary" arity="1"/> + <fsummary>Normalize characters to a utf8 binary of canonical equivalent + decomposed Unicode characters.</fsummary> + <desc> + <p>Converts a possibly deep list of characters and binaries + into a Normalized Form of canonical equivalent Decomposed + characters according to the Unicode standard.</p> + <p>Any binaries in the input must be encoded with utf8 + encoding.</p> + <p>The result is an utf8 encoded binary.</p> + <code> +2> unicode:characters_to_nfd_binary("abc..åäö"). +<<97,98,99,46,46,97,204,138,97,204,136,111,204,136>> +</code> + </desc> + </func> + + <func> + <name name="characters_to_nfkc_list" arity="1"/> + <fsummary>Normalize characters to a list of canonical equivalent + composed Unicode characters.</fsummary> + <desc> + <p>Converts a possibly deep list of characters and binaries + into a Normalized Form of compatibly equivalent Composed + characters according to the Unicode standard.</p> + <p>Any binaries in the input must be encoded with utf8 + encoding. + </p> + <p>The result is a list of characters.</p> + <code> +3> unicode:characters_to_nfkc_list([<<"abc..a">>,[778],$a,[776],$o,[776],[65299,65298]]). +"abc..åäö32" +</code> + </desc> + </func> + + <func> + <name name="characters_to_nfkc_binary" arity="1"/> + <fsummary>Normalize characters to a utf8 binary of compatibly equivalent + composed Unicode characters.</fsummary> + <desc> + <p>Converts a possibly deep list of characters and binaries + into a Normalized Form of compatibly equivalent Composed + characters according to the Unicode standard.</p> + <p>Any binaries in the input must be encoded with utf8 + encoding.</p> + <p>The result is an utf8 encoded binary.</p> + <code> +4> unicode:characters_to_nfkc_binary([<<"abc..a">>,[778],$a,[776],$o,[776],[65299,65298]]). +<<"abc..åäö32"/utf8>> +</code> + </desc> + </func> + + <func> + <name name="characters_to_nfkd_list" arity="1"/> + <fsummary>Normalize characters to a list of compatibly equivalent + decomposed Unicode characters.</fsummary> + <desc> + <p>Converts a possibly deep list of characters and binaries + into a Normalized Form of compatibly equivalent Decomposed + characters according to the Unicode standard.</p> + <p>Any binaries in the input must be encoded with utf8 + encoding. + </p> + <p>The result is a list of characters.</p> + <code> +1> unicode:characters_to_nfkd_list(["abc..åäö",[65299,65298]]). +[97,98,99,46,46,97,778,97,776,111,776,51,50] +</code> + </desc> + </func> + + <func> + <name name="characters_to_nfkd_binary" arity="1"/> + <fsummary>Normalize characters to a utf8 binary of compatibly equivalent + decomposed Unicode characters.</fsummary> + <desc> + <p>Converts a possibly deep list of characters and binaries + into a Normalized Form of compatibly equivalent Decomposed + characters according to the Unicode standard.</p> + <p>Any binaries in the input must be encoded with utf8 + encoding.</p> + <p>The result is an utf8 encoded binary.</p> + <code> +2> unicode:characters_to_nfkd_binary(["abc..åäö",[65299,65298]]). +<<97,98,99,46,46,97,204,138,97,204,136,111,204,136,51,50>> +</code> + </desc> + </func> + + <func> <name name="encoding_to_bom" arity="1"/> <fsummary>Create a binary UTF byte order mark from encoding.</fsummary> <type_desc variable="Bin"> diff --git a/lib/stdlib/doc/src/unicode_usage.xml b/lib/stdlib/doc/src/unicode_usage.xml index 7f79ac88a1..26dc46719e 100644 --- a/lib/stdlib/doc/src/unicode_usage.xml +++ b/lib/stdlib/doc/src/unicode_usage.xml @@ -5,7 +5,7 @@ <header> <copyright> <year>1999</year> - <year>2016</year> + <year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -62,6 +62,13 @@ <item><p>In Erlang/OTP 17.0, the encoding default for Erlang source files was switched to UTF-8.</p></item> + + <item><p>In Erlang/OTP 20.0, atoms and function can contain + Unicode characters. Module names, application names, and node + names are still restricted to the ISO Latin-1 range.</p> + <p>Support was added for normalizations forms in + <c>unicode</c> and the <c>string</c> module now handles + utf8-encoded binaries.</p></item> </list> <p>This section outlines the current Unicode support and gives some @@ -106,23 +113,27 @@ </item> </list> - <p>So, a conversion function must know not only one character at a time, - but possibly the whole sentence, the natural language to translate to, - the differences in input and output string length, and so on. - Erlang/OTP has currently no Unicode <c>to_upper</c>/<c>to_lower</c> - functionality, but publicly available libraries address these issues.</p> - - <p>Another example is the accented characters, where the same glyph has two - different representations. The Swedish letter "ö" is one example. - The Unicode standard has a code point for it, but you can also write it - as "o" followed by "U+0308" (Combining Diaeresis, with the simplified - meaning that the last letter is to have "¨" above). They have the same - glyph. They are for most purposes the same, but have different - representations. For example, MacOS X converts all filenames to use - Combining Diaeresis, while most other programs (including Erlang) try to - hide that by doing the opposite when, for example, listing directories. - However it is done, it is usually important to normalize such - characters to avoid confusion.</p> + <p>So, a conversion function must know not only one character at a + time, but possibly the whole sentence, the natural language to + translate to, the differences in input and output string length, + and so on. Erlang/OTP has currently no Unicode + <c>uppercase</c>/<c>lowercase</c> functionality with language + specific handling, but publicly available libraries address these + issues.</p> + + <p>Another example is the accented characters, where the same + glyph has two different representations. The Swedish letter "ö" is + one example. The Unicode standard has a code point for it, but + you can also write it as "o" followed by "U+0308" (Combining + Diaeresis, with the simplified meaning that the last letter is to + have "¨" above). They have the same glyph, user perceived + character. They are for most purposes the same, but have different + representations. For example, MacOS X converts all filenames to + use Combining Diaeresis, while most other programs (including + Erlang) try to hide that by doing the opposite when, for example, + listing directories. However it is done, it is usually important + to normalize such characters to avoid confusion. + </p> <p>The list of examples can be made long. One need a kind of knowledge that was not needed when programs only considered one or two languages. The @@ -269,13 +280,13 @@ them. In some cases functionality has been added to already existing interfaces (as the <seealso marker="stdlib:string"><c>string</c></seealso> module now can - handle lists with any code points). In some cases new + handle strings with any code points). In some cases new functionality or options have been added (as in the <seealso marker="stdlib:io"><c>io</c></seealso> module, the file handling, the <seealso marker="stdlib:unicode"><c>unicode</c></seealso> module, and - the bit syntax). Today most modules in <c>Kernel</c> and - <c>STDLIB</c>, as well as the VM are Unicode-aware.</p> + the bit syntax). Today most modules in Kernel and + STDLIB, as well as the VM are Unicode-aware.</p> </item> <tag>File I/O</tag> <item> @@ -339,11 +350,13 @@ <tag>The language</tag> <item> <p>Having the source code in UTF-8 also allows you to write string - literals containing Unicode characters with code points > 255, - although atoms, module names, and function names are restricted to - the ISO Latin-1 range. Binary literals, where you use type + literals, function names, and atoms containing Unicode + characters with code points > 255. + Module names, application names, and node names are still restricted + to the ISO Latin-1 range. Binary literals, where you use type <c>/utf8</c>, can also be expressed using Unicode characters > 255. - Having module names using characters other than 7-bit ASCII can cause + Having module names or application names using characters other than + 7-bit ASCII can cause trouble on operating systems with inconsistent file naming schemes, and can hurt portability, so it is not recommended.</p> <p>EEP 40 suggests that the language is also to allow for Unicode @@ -432,15 +445,17 @@ external_charlist() = maybe_improper_list(char() | external_unicode_binary() | <section> <title>Basic Language Support</title> - <p><marker id="unicode_in_erlang"/>As from Erlang/OTP R16, Erlang source - files can be written in UTF-8 or bytewise (<c>latin1</c>) encoding. For - information about how to state the encoding of an Erlang source file, see - the <seealso marker="stdlib:epp#encoding"><c>epp(3)</c></seealso> module. - Strings and comments can be written using Unicode, but functions must - still be named using characters from the ISO Latin-1 character set, and - atoms are restricted to the same ISO Latin-1 range. These restrictions in - the language are of course independent of the encoding of the source - file.</p> + <p><marker id="unicode_in_erlang"/>As from Erlang/OTP R16, Erlang + source files can be written in UTF-8 or bytewise (<c>latin1</c>) + encoding. For information about how to state the encoding of an + Erlang source file, see the <seealso + marker="stdlib:epp#encoding"><c>epp(3)</c></seealso> module. As + from Erlang/OTP R16, strings and comments can be written using + Unicode. As from Erlang/OTP 20, also atoms and functions can be + written using Unicode. Modules, applications, and nodes must still be + named using characters from the ISO Latin-1 character set. (These + restrictions in the language are independent of the encoding of + the source file.)</p> <section> <title>Bit Syntax</title> @@ -765,8 +780,8 @@ Eshell V5.10.1 (abort with ^G) file system). The Unicode character list is used to denote filenames or directory names. If the file system content is listed, you also get Unicode lists as return value. The support - lies in the <c>Kernel</c> and <c>STDLIB</c> modules, which is why - most applications (that does not explicitly require the filenames + lies in the Kernel and STDLIB modules, which is why + most applications (that do not explicitly require the filenames to be in the ISO Latin-1 range) benefit from the Unicode support without change.</p> @@ -843,7 +858,7 @@ Eshell V5.10.1 (abort with ^G) <title>Notes About Raw Filenames</title> <marker id="notes-about-raw-filenames"/> <p>Raw filenames were introduced together with Unicode filename support - in <c>ERTS</c> 5.8.2 (Erlang/OTP R14B01). The reason "raw + in ERTS 5.8.2 (Erlang/OTP R14B01). The reason "raw filenames" were introduced in the system was to be able to represent filenames, specified in different encodings on the same system, @@ -970,7 +985,7 @@ Eshell V5.10.1 (abort with ^G) <p>Fortunately, most textual data has been stored in lists and range checking has been sparse, so modules like <c>string</c> work well for - Unicode lists with little need for conversion or extension.</p> + Unicode strings with little need for conversion or extension.</p> <p>Some modules are, however, changed to be explicitly Unicode-aware. These modules include:</p> @@ -1021,18 +1036,17 @@ Eshell V5.10.1 (abort with ^G) has extensive support for Unicode text.</p></item> </taglist> - <p>The <seealso marker="stdlib:string"><c>string</c></seealso> module works - perfectly for Unicode strings and ISO Latin-1 strings, except the - language-dependent functions - <seealso marker="stdlib:string#to_upper/1"><c>string:to_upper/1</c></seealso> - and - <seealso marker="stdlib:string#to_lower/1"><c>string:to_lower/1</c></seealso>, - which are only correct for the ISO Latin-1 character set. These two - functions can never function correctly for Unicode characters in their - current form, as there are language and locale issues as well as - multi-character mappings to consider when converting text between cases. - Converting case in an international environment is a large subject not - yet addressed in OTP.</p> + <p>The <seealso marker="stdlib:string"><c>string</c></seealso> + module works perfectly for Unicode strings and ISO Latin-1 + strings, except the language-dependent functions <seealso + marker="stdlib:string#uppercase/1"><c>string:uppercase/1</c></seealso> + and <seealso + marker="stdlib:string#lowercase/1"><c>string:lowercase/1</c></seealso>. + These two functions can never function correctly for Unicode + characters in their current form, as there are language and locale + issues to consider when converting text between cases. Converting + case in an international environment is a large subject not yet + addressed in OTP.</p> </section> <section> diff --git a/lib/stdlib/doc/src/zip.xml b/lib/stdlib/doc/src/zip.xml index de23608046..0b5eac1e16 100644 --- a/lib/stdlib/doc/src/zip.xml +++ b/lib/stdlib/doc/src/zip.xml @@ -138,7 +138,7 @@ <p>File information as in <seealso marker="kernel:file#read_file_info/1"> <c>file:read_file_info/1</c></seealso> - in <c>Kernel</c></p> + in Kernel</p> </item> <tag><c>comment</c></tag> <item> @@ -345,7 +345,7 @@ prepended to filenames when extracting them from the zip archive. (Acting like <seealso marker="kernel:file#set_cwd/1"> - <c>file:set_cwd/1</c></seealso> in <c>Kernel</c>, + <c>file:set_cwd/1</c></seealso> in Kernel, but without changing the global <c>cwd</c> property.)</p> </item> </taglist> @@ -420,7 +420,7 @@ (<c>cwd</c>). This is prepended to filenames when adding them, although not in the zip archive (acting like <seealso marker="kernel:file#set_cwd/1"> - <c>file:set_cwd/1</c></seealso> in <c>Kernel</c>, but without + <c>file:set_cwd/1</c></seealso> in Kernel, but without changing the global <c>cwd</c> property.).</p> </item> <tag><c>{compress, <anno>What</anno>}</c></tag> |