diff options
Diffstat (limited to 'lib/stdlib/doc/src')
27 files changed, 1229 insertions, 280 deletions
diff --git a/lib/stdlib/doc/src/Makefile b/lib/stdlib/doc/src/Makefile index e7ea38c5c3..5c6b714f80 100644 --- a/lib/stdlib/doc/src/Makefile +++ b/lib/stdlib/doc/src/Makefile @@ -71,7 +71,6 @@ XML_REF3_FILES = \ gen_statem.xml \ io.xml \ io_lib.xml \ - lib.xml \ lists.xml \ log_mf_h.xml \ maps.xml \ @@ -98,6 +97,7 @@ XML_REF3_FILES = \ sys.xml \ timer.xml \ unicode.xml \ + uri_string.xml \ win32reg.xml \ zip.xml @@ -162,7 +162,7 @@ clean clean_docs: rm -f errs core *~ $(SPECDIR)/specs_erl_id_trans.xml: - escript $(SPECS_EXTRACTOR) $(SPECS_FLAGS) \ + $(gen_verbose)escript $(SPECS_EXTRACTOR) $(SPECS_FLAGS) \ -o$(dir $@) -module erl_id_trans # ---------------------------------------------------- diff --git a/lib/stdlib/doc/src/c.xml b/lib/stdlib/doc/src/c.xml index 7666699183..697e1715e7 100644 --- a/lib/stdlib/doc/src/c.xml +++ b/lib/stdlib/doc/src/c.xml @@ -94,6 +94,15 @@ </func> <func> + <name name="erlangrc" arity="1"/> + <fsummary>Load an erlang resource file.</fsummary> + <desc> + <p>Search <c>PathList</c> and load <c>.erlang</c> resource file if + found.</p> + </desc> + </func> + + <func> <name name="flush" arity="0"/> <fsummary>Flush any messages sent to the shell.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/calendar.xml b/lib/stdlib/doc/src/calendar.xml index 65b3edcdf6..6b4fa7f98a 100644 --- a/lib/stdlib/doc/src/calendar.xml +++ b/lib/stdlib/doc/src/calendar.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2016</year> + <year>1996</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -317,6 +317,32 @@ </func> <func> + <name name="rfc3339_to_system_time" arity="1"/> + <name name="rfc3339_to_system_time" arity="2"/> + <fsummary>Convert from RFC 3339 timestamp to system time.</fsummary> + <type name="rfc3339_string"/> + <type name="rfc3339_time_unit"/> + <desc> + <p>Converts an RFC 3339 timestamp into system time. The data format + of RFC 3339 timestamps is described by + <url href="https://www.ietf.org/rfc/rfc3339.txt">RFC 3339</url>.</p> + <p>Valid option:</p> + <taglist> + <tag><c>{unit, Unit}</c></tag> + <item><p>The time unit of the return value. + The default is <c>second</c>.</p> + </item> + </taglist> + <pre> +1> <input>calendar:rfc3339_to_system_time("2018-02-01T16:17:58+01:00").</input> +1517498278 +2> <input>calendar:rfc3339_to_system_time("2018-02-01 15:18:02.088Z", + [{unit, nanosecond}]).</input> +1517498282088000000</pre> + </desc> + </func> + + <func> <name name="seconds_to_daystime" arity="1"/> <fsummary>Compute days and time from seconds.</fsummary> <desc> @@ -339,6 +365,71 @@ </func> <func> + <name name="system_time_to_local_time" arity="2"/> + <fsummary>Convert system time to local date and time.</fsummary> + <desc> + <p>Converts a specified system time into local date and time.</p> + </desc> + </func> + + <func> + <name name="system_time_to_rfc3339" arity="1"/> + <name name="system_time_to_rfc3339" arity="2"/> + <fsummary>Convert from system to RFC 3339 timestamp.</fsummary> + <type name="offset"/> + <type name="rfc3339_string"/> + <type name="rfc3339_time_unit"/> + <desc> + <p>Converts a system time into an RFC 3339 timestamp. The data format + of RFC 3339 timestamps is described by + <url href="https://www.ietf.org/rfc/rfc3339.txt">RFC 3339</url>. + The data format of offsets is also described by RFC 3339.</p> + <p>Valid options:</p> + <taglist> + <tag><c>{offset, Offset}</c></tag> + <item><p>The offset, either a string or an integer, to be + included in the formatted string. + An empty string, which is the default, is interpreted + as local time. A non-empty string is included as is. + The time unit of the integer is the same as the one + of <c><anno>Time</anno></c>.</p> + </item> + <tag><c>{time_designator, Character}</c></tag> + <item><p>The character used as time designator, that is, + the date and time separator. The default is <c>$T</c>.</p> + </item> + <tag><c>{unit, Unit}</c></tag> + <item><p>The time unit of <c><anno>Time</anno></c>. The + default is <c>second</c>. If some other unit is given + (<c>millisecond</c>, <c>microsecond</c>, or + <c>nanosecond</c>), the formatted string includes a + fraction of a second.</p> + </item> + </taglist> + <pre> +1> <input>calendar:system_time_to_rfc3339(erlang:system_time(second)).</input> +"2018-04-23T14:56:28+02:00" +2> <input>calendar:system_time_to_rfc3339(erlang:system_time(second), + [{offset, "-02:00"}]).</input> +"2018-04-23T10:56:52-02:00" +3> <input>calendar:system_time_to_rfc3339(erlang:system_time(second), + [{offset, -7200}]).</input> +"2018-04-23T10:57:05-02:00" +4> <input>calendar:system_time_to_rfc3339(erlang:system_time(millisecond), + [{unit, millisecond}, {time_designator, $\s}, {offset, "Z"}]).</input> +"2018-04-23 12:57:20.482Z"</pre> + </desc> + </func> + + <func> + <name name="system_time_to_universal_time" arity="2"/> + <fsummary>Convert system time to universal date and time.</fsummary> + <desc> + <p>Converts a specified system time into universal date and time.</p> + </desc> + </func> + + <func> <name name="time_difference" arity="2"/> <fsummary>Compute the difference between two times (deprecated). </fsummary> diff --git a/lib/stdlib/doc/src/erl_tar.xml b/lib/stdlib/doc/src/erl_tar.xml index 337028568a..68fa071090 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>2017</year> + <year>2003</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -90,8 +90,8 @@ <section> <title>Other Storage Media</title> - <p>The <seealso marker="inets:ftp"><c>ftp</c></seealso> - module (Inets) normally accesses the tar file on disk using + <p>The <seealso marker="ftp:ftp"><c>ftp</c></seealso> + module normally accesses the tar file on disk using the <seealso marker="kernel:file"><c>file</c></seealso> module. When other needs arise, you can define your own low-level Erlang functions to perform the writing and reading on the storage media; @@ -136,6 +136,9 @@ <v>Filename = filename()|{NameInArchive,FilenameOrBin}</v> <v>Options = [Option]</v> <v>Option = dereference|verbose|{chunks,ChunkSize}</v> + <v>|{atime,non_neg_integer()}|{mtime,non_neg_integer()}</v> + <v>|{ctime,non_neg_integer()}|{uid,non_neg_integer()}</v> + <v>|{gid,non_neg_integer()}</v> <v>ChunkSize = positive_integer()</v> <v>RetValue = ok|{error,{Filename,Reason}}</v> <v>Reason = term()</v> @@ -167,6 +170,42 @@ <seealso marker="ssh:ssh_sftp#open_tar/3"> <c>ssh_sftp:open_tar/3</c></seealso>.</p> </item> + <tag><c>{atime,non_neg_integer()}</c></tag> + <item> + <p>Sets the last time, as + <seealso marker="erts:time_correction#POSIX_Time"> + POSIX time</seealso>, when the file was read. See also + <seealso marker="kernel:file#read_file_info/1"> + <c>file:read_file_info/1</c></seealso>.</p> + </item> + <tag><c>{mtime,non_neg_integer()}</c></tag> + <item> + <p>Sets the last time, as + <seealso marker="erts:time_correction#POSIX_Time"> + POSIX time</seealso>, when the file was written. See also + <seealso marker="kernel:file#read_file_info/1"> + <c>file:read_file_info/1</c></seealso>.</p> + </item> + <tag><c>{ctime,non_neg_integer()}</c></tag> + <item> + <p>Sets the time, as + <seealso marker="erts:time_correction#POSIX_Time"> + POSIX time</seealso>, when the file was created. See also + <seealso marker="kernel:file#read_file_info/1"> + <c>file:read_file_info/1</c></seealso>.</p> + </item> + <tag><c>{uid,non_neg_integer()}</c></tag> + <item> + <p>Sets the file owner. + <seealso marker="kernel:file#read_file_info/1"> + <c>file:read_file_info/1</c></seealso>.</p> + </item> + <tag><c>{gid,non_neg_integer()}</c></tag> + <item> + <p>Sets the group that the file owner belongs to. + <seealso marker="kernel:file#read_file_info/1"> + <c>file:read_file_info/1</c></seealso>.</p> + </item> </taglist> </desc> </func> @@ -378,7 +417,7 @@ <v>Reason = term()</v> </type> <desc> - <p>Cconverts an error reason term to a human-readable error message + <p>Converts an error reason term to a human-readable error message string.</p> </desc> </func> diff --git a/lib/stdlib/doc/src/ets.xml b/lib/stdlib/doc/src/ets.xml index 51e35cd2df..1995262145 100644 --- a/lib/stdlib/doc/src/ets.xml +++ b/lib/stdlib/doc/src/ets.xml @@ -49,14 +49,16 @@ associated with each key. A <c>bag</c> or <c>duplicate_bag</c> table can have many objects associated with each key.</p> + <marker id="max_ets_tables"></marker> <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 + <c>ERL_MAX_ETS_TABLES</c> or the command line option + <seealso marker="erts:erl#+e"><c>+e</c></seealso> 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 @@ -487,6 +489,11 @@ Error: fun containing local Erlang function calls <p>The pid of the heir of the table, or <c>none</c> if no heir is set.</p> </item> + <tag><c>{id,</c><seealso marker="#type-tid"> + <c>tid()</c></seealso><c>}</c></tag> + <item> + <p>The table identifier.</p> + </item> <tag><c>{keypos, integer() >= 1}</c></tag> <item> <p>The key position.</p> @@ -1074,10 +1081,13 @@ ets:select(Table, MatchSpec),</code> </item> <tag><c>named_table</c></tag> <item> - <p>If this option is present, name <c><anno>Name</anno></c> is - associated with the table identifier. The name can then - be used instead of the table identifier in subsequent - operations.</p> + <p>If this option is present, the table is registered under its + <c><anno>Name</anno></c> which can then be used instead of the + table identifier in subsequent operations.</p> + <p>The function will also return the <c><anno>Name</anno></c> + instead of the table identifier. To get the table identifier of a + named table, use + <seealso marker="#whereis/1"><c>whereis/1</c></seealso>.</p> </item> <tag><c>{keypos,<anno>Pos</anno>}</c></tag> <item> @@ -1961,7 +1971,7 @@ true</pre> The return value is a list of the new counter values from each update operation in the same order as in the operation list. If an empty list is specified, nothing is updated and an empty list is - returned. If the function fails, no updates is done.</p> + returned. If the function fails, no updates are done.</p> <p>The specified <c><anno>Key</anno></c> is used to identify the object by either <em>matching</em> the key of an object in a <c>set</c> table, or <em>compare equal</em> to the key of an object in an @@ -2037,6 +2047,21 @@ true</pre> </list> </desc> </func> + + <func> + <name name="whereis" arity="1"/> + <fsummary>Retrieves the tid() of a named table.</fsummary> + <desc> + <p>This function returns the + <seealso marker="#type-tid"><c>tid()</c></seealso> of the named table + identified by <c><anno>TableName</anno></c>, or <c>undefined</c> if + no such table exists. The <c>tid()</c> can be used in place of the + table name in all operations, which is slightly faster since the name + does not have to be resolved on each call.</p> + <p>If the table is deleted, the <c>tid()</c> will be invalid even if + another named table is created with the same name.</p> + </desc> + </func> </funcs> </erlref> diff --git a/lib/stdlib/doc/src/filelib.xml b/lib/stdlib/doc/src/filelib.xml index 11762a3c5a..3b5be75bc0 100644 --- a/lib/stdlib/doc/src/filelib.xml +++ b/lib/stdlib/doc/src/filelib.xml @@ -45,6 +45,30 @@ <p>For more information about raw filenames, see the <seealso marker="kernel:file"><c>file</c></seealso> module.</p> + + <note> + <p> + Functionality in this module generally assumes valid input and + does not necessarily fail on input that does not use a valid + encoding, but may instead very likely produce invalid output. + </p> + <p> + File operations used to accept filenames containing + null characters (integer value zero). This caused + the name to be truncated and in some cases arguments + to primitive operations to be mixed up. Filenames + containing null characters inside the filename + are now <em>rejected</em> and will cause primitive + file operations to fail. + </p> + </note> + <warning><p> + Currently null characters at the end of the filename + will be accepted by primitive file operations. Such + filenames are however still documented as invalid. The + implementation will also change in the future and + reject such filenames. + </p></warning> </description> <datatypes> @@ -193,6 +217,11 @@ <p>Other characters represent themselves. Only filenames that have exactly the same character in the same position match. Matching is case-sensitive, for example, "a" does not match "A".</p> + <p>Directory separators must always be written as <c>/</c>, even on + Windows.</p> + <p>A character preceded by <c>\</c> loses its special meaning. Note + that <c>\</c> must be written as <c>\\</c> in a string literal. + For example, "\\?*" will match any filename starting with <c>?</c>.</p> <p>Notice that multiple "*" characters are allowed (as in Unix wildcards, but opposed to Windows/DOS wildcards).</p> <p><em>Examples:</em></p> diff --git a/lib/stdlib/doc/src/filename.xml b/lib/stdlib/doc/src/filename.xml index 1135a6dd80..ce19f70df0 100644 --- a/lib/stdlib/doc/src/filename.xml +++ b/lib/stdlib/doc/src/filename.xml @@ -46,7 +46,10 @@ filename by removing redundant directory separators, use <seealso marker="#join/1"><c>join/1</c></seealso>.</p> - <p>The module supports raw filenames in the way that if a binary is + <p> + The module supports + <seealso marker="unicode_usage#notes-about-raw-filenames">raw + filenames</seealso> in the way that if a binary is present, or the filename cannot be interpreted according to the return value of <seealso marker="kernel:file#native_name_encoding/0"> <c>file:native_name_encoding/0</c></seealso>, a raw filename is also @@ -56,6 +59,30 @@ (the join operation is performed of course). For more information about raw filenames, see the <seealso marker="kernel:file"><c>file</c></seealso> module.</p> + + <note> + <p> + Functionality in this module generally assumes valid input and + does not necessarily fail on input that does not use a valid + encoding, but may instead very likely produce invalid output. + </p> + <p> + File operations used to accept filenames containing + null characters (integer value zero). This caused + the name to be truncated and in some cases arguments + to primitive operations to be mixed up. Filenames + containing null characters inside the filename + are now <em>rejected</em> and will cause primitive + file operations to fail. + </p> + </note> + <warning><p> + Currently null characters at the end of the filename + will be accepted by primitive file operations. Such + filenames are however still documented as invalid. The + implementation will also change in the future and + reject such filenames. + </p></warning> </description> <datatypes> <datatype> @@ -558,6 +585,7 @@ unsafe</pre> ["a:/","msdev","include"]</pre> </desc> </func> + </funcs> </erlref> diff --git a/lib/stdlib/doc/src/gb_sets.xml b/lib/stdlib/doc/src/gb_sets.xml index 7bfe477a11..2a3785dc27 100644 --- a/lib/stdlib/doc/src/gb_sets.xml +++ b/lib/stdlib/doc/src/gb_sets.xml @@ -83,6 +83,8 @@ </item> <item><seealso marker="#is_element/2"><c>is_element/2</c></seealso> </item> + <item><seealso marker="#is_empty/1"><c>is_empty/1</c></seealso> + </item> <item><seealso marker="#is_set/1"><c>is_set/1</c></seealso> </item> <item><seealso marker="#is_subset/2"><c>is_subset/2</c></seealso> diff --git a/lib/stdlib/doc/src/gen_event.xml b/lib/stdlib/doc/src/gen_event.xml index 012737c390..6170801e87 100644 --- a/lib/stdlib/doc/src/gen_event.xml +++ b/lib/stdlib/doc/src/gen_event.xml @@ -207,7 +207,7 @@ gen_event:stop -----> Module:terminate/2 </item> <item> <p>If the event handler is deleted later, the event manager - sends a message<c>{gen_event_EXIT,Handler,Reason}</c> to + sends a message <c>{gen_event_EXIT,Handler,Reason}</c> to the calling process. <c>Reason</c> is one of the following:</p> <list type="bulleted"> <item> @@ -458,8 +458,7 @@ gen_event:stop -----> Module:terminate/2 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>. + <seealso marker="kernel:logger"><c>logger(3)</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 event manager to diff --git a/lib/stdlib/doc/src/gen_server.xml b/lib/stdlib/doc/src/gen_server.xml index 7d137fc772..27edbc8de7 100644 --- a/lib/stdlib/doc/src/gen_server.xml +++ b/lib/stdlib/doc/src/gen_server.xml @@ -60,6 +60,8 @@ gen_server:abcast -----> Module:handle_cast/2 - -----> Module:handle_info/2 +- -----> Module:handle_continue/2 + - -----> Module:terminate/2 - -----> Module:code_change/3</pre> @@ -88,6 +90,13 @@ gen_server:abcast -----> Module:handle_cast/2 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 server.</p> + + <p>If the <c>gen_server</c> process needs to perform an action + immediately after initialization or to break the execution of a + callback into multiple steps, it can return <c>{continue,Continue}</c> + in place of the time-out or hibernation value, which will immediately + invoke the <c>handle_continue/2</c> callback.</p> + </description> <funcs> @@ -477,8 +486,7 @@ gen_server:abcast -----> Module:handle_cast/2 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>. + <seealso marker="kernel:logger"><c>logger(3)</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 server to @@ -610,12 +618,15 @@ gen_server:abcast -----> Module:handle_cast/2 <v>State = term()</v> <v>Result = {reply,Reply,NewState} | {reply,Reply,NewState,Timeout}</v> <v> | {reply,Reply,NewState,hibernate}</v> + <v> | {reply,Reply,NewState,{continue,Continue}}</v> <v> | {noreply,NewState} | {noreply,NewState,Timeout}</v> <v> | {noreply,NewState,hibernate}</v> + <v> | {noreply,NewState,{continue,Continue}}</v> <v> | {stop,Reason,Reply,NewState} | {stop,Reason,NewState}</v> <v> Reply = term()</v> <v> NewState = term()</v> <v> Timeout = int()>=0 | infinity</v> + <v> Continue = term()</v> <v> Reason = term()</v> </type> <desc> @@ -673,9 +684,11 @@ gen_server:abcast -----> Module:handle_cast/2 <v>State = term()</v> <v>Result = {noreply,NewState} | {noreply,NewState,Timeout}</v> <v> | {noreply,NewState,hibernate}</v> + <v> | {noreply,NewState,{continue,Continue}}</v> <v> | {stop,Reason,NewState}</v> <v> NewState = term()</v> <v> Timeout = int()>=0 | infinity</v> + <v> Continue = term()</v> <v> Reason = term()</v> </type> <desc> @@ -690,6 +703,41 @@ gen_server:abcast -----> Module:handle_cast/2 </func> <func> + <name>Module:handle_continue(Continue, State) -> Result</name> + <fsummary>Handle a continue instruction.</fsummary> + <type> + <v>Continue = term()</v> + <v>State = term()</v> + <v>Result = {noreply,NewState} | {noreply,NewState,Timeout}</v> + <v> | {noreply,NewState,hibernate}</v> + <v> | {noreply,NewState,{continue,Continue}}</v> + <v> | {stop,Reason,NewState}</v> + <v> NewState = term()</v> + <v> Timeout = int()>=0 | infinity</v> + <v> Continue = term()</v> + <v> Reason = normal | term()</v> + </type> + <desc> + <note> + <p>This callback is optional, so callback modules need to + export it only if they return <c>{continue,Continue}</c> + from another callback. If continue is used and the callback + is not implemented, the process will exit with <c>undef</c> + error.</p> + </note> + <p>This function is called by a <c>gen_server</c> process whenever + a previous callback returns <c>{continue, Continue}</c>. + <c>handle_continue/2</c> is invoked immediately after the previous + callback, which makes it useful for performing work after + initialization or for splitting the work in a callback in + multiple steps, updating the process state along the way.</p> + <p>For a description of the other arguments and possible return values, + see <seealso marker="#Module:handle_call/3"> + <c>Module:handle_call/3</c></seealso>.</p> + </desc> + </func> + + <func> <name>Module:handle_info(Info, State) -> Result</name> <fsummary>Handle an incoming message.</fsummary> <type> @@ -697,6 +745,7 @@ gen_server:abcast -----> Module:handle_cast/2 <v>State = term()</v> <v>Result = {noreply,NewState} | {noreply,NewState,Timeout}</v> <v> | {noreply,NewState,hibernate}</v> + <v> | {noreply,NewState,{continue,Continue}}</v> <v> | {stop,Reason,NewState}</v> <v> NewState = term()</v> <v> Timeout = int()>=0 | infinity</v> @@ -726,7 +775,7 @@ gen_server:abcast -----> Module:handle_cast/2 <type> <v>Args = term()</v> <v>Result = {ok,State} | {ok,State,Timeout} | {ok,State,hibernate}</v> - <v> | {stop,Reason} | ignore</v> + <v> | {ok,State,{continue,Continue}} | {stop,Reason} | ignore</v> <v> State = term()</v> <v> Timeout = int()>=0 | infinity</v> <v> Reason = term()</v> @@ -811,8 +860,7 @@ gen_server:abcast -----> Module:handle_cast/2 <c>shutdown</c>, or <c>{shutdown,Term}</c>, the <c>gen_server</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> + <seealso marker="kernel:logger"><c>logger(3)</c></seealso>.</p> </desc> </func> </funcs> diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index 574f488e91..a808d3af55 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>2017</year> + <year>2016</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -32,7 +32,68 @@ <modulesummary>Generic state machine behavior.</modulesummary> <description> <p> - This behavior module provides a state machine. Two + <c>gen_statem</c> provides a generic state machine behaviour + and replaces its predecessor + <seealso marker="gen_fsm"><c>gen_fsm</c></seealso> + since Erlang/OTP 20.0. + </p> + <p> + This reference manual describes types generated from the types + in the <c>gen_statem</c> source code, so they are correct. + However, the generated descriptions also reflect the type hiearchy, + which makes them kind of hard to read. + </p> + <p> + To get an overview of the concepts and operation of <c>gen_statem</c>, + do read the + <seealso marker="doc/design_principles:statem"> + <c>gen_statem</c> Behaviour + </seealso> + in + <seealso marker="doc/design_principles:users_guide"> + OTP Design Principles + </seealso> + which frequently links back to this reference manual to avoid + containing detailed facts that may rot by age. + </p> + <note> + <p> + This behavior appeared in Erlang/OTP 19.0. + In OTP 19.1 a backwards incompatible change of + the return tuple from + <seealso marker="#Module:init/1"><c>Module:init/1</c></seealso> + was made and the mandatory callback function + <seealso marker="#Module:callback_mode/0"> + <c>Module:callback_mode/0</c> + </seealso> + was introduced. In OTP 20.0 the + <seealso marker="#type-generic_timeout"><c>generic timeouts</c></seealso> + were added. + </p> + </note> + <p> + <c>gen_statem</c> has got the same features that + <seealso marker="gen_fsm"><c>gen_fsm</c></seealso> + had and adds some really useful: + </p> + <list type="bulleted"> + <item>Co-located 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, <c>sys</c> traceable + </item> + <item>Multiple <c>sys</c> traceable replies</item> + </list> + + + <p> + Two <seealso marker="#type-callback_mode"><em>callback modes</em></seealso> are supported: </p> @@ -50,34 +111,6 @@ </p> </item> </list> - <note> - <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. - 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 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>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>, @@ -148,7 +181,7 @@ erlang:'!' -----> Module:StateName/3 is <c>state_functions</c>, the state must be an atom and 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 + This co-locates all code for a specific state in one function as the <c>gen_statem</c> engine branches depending on state name. Note the fact that the callback function @@ -207,8 +240,10 @@ erlang:'!' -----> Module:StateName/3 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. + Another way to do it is to insert an event at the state transition, + and/or to use a dedicated state transition function, + but that is something you will have to remember + at every state transition to the state(s) that need it. </p> <note> <p>If you in <c>gen_statem</c>, for example, postpone @@ -252,6 +287,16 @@ erlang:'!' -----> Module:StateName/3 to use after every event; see <seealso marker="erts:erlang#hibernate/3"><c>erlang:hibernate/3</c></seealso>. </p> + <p> + There is also a server start option + <seealso marker="#type-hibernate_after_opt"> + <c>{hibernate_after, Timeout}</c> + </seealso> + for + <seealso marker="#start/3"><c>start/3,4</c></seealso> or + <seealso marker="#start_link/3"><c>start_link/3,4</c></seealso> + that may be used to automatically hibernate the server. + </p> </description> <section> @@ -668,9 +713,9 @@ handle_event(_, _, State, Data) -> <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. + should transform the state, + it is regarded as a state rename and not a state change, + which will not cause a state enter call. </p> <p> Note that a state enter call <em>will</em> be done @@ -688,12 +733,19 @@ handle_event(_, _, State, Data) -> <p> Transition options can be set by <seealso marker="#type-action">actions</seealso> - and they modify how the state transition is done: + and modify the state transition. + Here are the sequence of steps for a state transition: </p> <list type="ordered"> <item> <p> - If the state changes, is the initial state, + If + <seealso marker="#type-state_enter"> + <em>state enter calls</em> + </seealso> + are used, and either: + the state changes, it is the initial state, + or one of the callback results <seealso marker="#type-state_callback_result"> <c>repeat_state</c> </seealso> @@ -701,16 +753,21 @@ handle_event(_, _, State, Data) -> <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 + is used; the <c>gen_statem</c> calls the new state callback with arguments - <seealso marker="#type-state_enter">(enter, OldState, Data)</seealso>. + <seealso marker="#type-state_enter"><c>(enter, OldState, Data)</c></seealso>. + </p> + <p> Any - <seealso marker="#type-enter_action"><c>actions</c></seealso> + <seealso marker="#type-enter_action">actions</seealso> returned from this call are handled as if they were - appended to the actions - returned by the state callback that changed states. + appended to the actions + returned by the state callback that caused the state entry. + </p> + <p> + Should this state enter call return any of + the mentioned <c>repeat_*</c> callback results + it is repeated again, with the updated <c>Data</c>. </p> </item> <item> @@ -739,7 +796,7 @@ handle_event(_, _, State, Data) -> All events stored with <seealso marker="#type-action"><c>action()</c></seealso> <c>next_event</c> - are inserted to be processed before the other queued events. + are inserted to be processed before previously queued events. </p> </item> <item> @@ -753,7 +810,9 @@ handle_event(_, _, State, Data) -> 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. + the newest received event; + that is after already queued events + such as inserted and postponed events. </p> <p> Any event cancels an @@ -791,7 +850,7 @@ handle_event(_, _, State, Data) -> 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. + and we start again from the top of this sequence. </p> </item> </list> @@ -816,13 +875,19 @@ handle_event(_, _, State, Data) -> <seealso marker="proc_lib#hibernate/3"><c>proc_lib:hibernate/3</c></seealso> before going into <c>receive</c> to wait for a new external event. - If there are enqueued events, - to prevent receiving any new event, an - <seealso marker="erts:erlang#garbage_collect/0"><c>erlang:garbage_collect/0</c></seealso> - is done instead to simulate - that the <c>gen_statem</c> entered hibernation - and immediately got awakened by the oldest enqueued event. </p> + <note> + <p> + If there are enqueued events to process + when hibrnation is requested, + this is optimized by not hibernating but instead calling + <seealso marker="erts:erlang#garbage_collect/0"> + <c>erlang:garbage_collect/0</c> + </seealso> + to simulate that the <c>gen_statem</c> entered hibernation + and immediately got awakened by an enqueued event. + </p> + </note> </desc> </datatype> <datatype> @@ -857,7 +922,7 @@ handle_event(_, _, State, Data) -> 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. + received external event, but after already queued events. </p> <p> Note that it is not possible nor needed to cancel this time-out, @@ -943,7 +1008,9 @@ handle_event(_, _, State, Data) -> 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> + <seealso marker="erts:erlang#start_timer/4"> + <c>erlang:start_timer/4</c> + </seealso> for details. </p> <p> @@ -969,7 +1036,9 @@ handle_event(_, _, State, Data) -> </p> <p> Actions that set - <seealso marker="#type-transition_option">transition options</seealso> + <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 @@ -981,7 +1050,9 @@ handle_event(_, _, State, Data) -> <item> <p> Sets the - <seealso marker="#type-transition_option"><c>transition_option()</c></seealso> + <seealso marker="#type-transition_option"> + <c>transition_option()</c> + </seealso> <seealso marker="#type-postpone"><c>postpone()</c></seealso> for this state transition. This action is ignored when returned from @@ -994,7 +1065,11 @@ handle_event(_, _, State, Data) -> <tag><c>next_event</c></tag> <item> <p> - Stores the specified <c><anno>EventType</anno></c> + This action does not set any + <seealso marker="#type-transition_option"> + <c>transition_option()</c> + </seealso> + but instead stores the specified <c><anno>EventType</anno></c> and <c><anno>EventContent</anno></c> for insertion after all actions have been executed. </p> @@ -1066,15 +1141,15 @@ handle_event(_, _, State, Data) -> <seealso marker="#type-transition_option">transition options</seealso>. </p> <taglist> - <tag><c>Timeout</c></tag> + <tag><c>Time</c></tag> <item> <p> - Short for <c>{timeout,Timeout,Timeout}</c>, that is, + Short for <c>{timeout,Time,Time}</c>, that is, the time-out message is the time-out time. This form exists to make the <seealso marker="#state callback">state callback</seealso> - return value <c>{next_state,NextState,NewData,Timeout}</c> - allowed like for <c>gen_fsm</c>'s + return value <c>{next_state,NextState,NewData,Time}</c> + allowed like for <c>gen_fsm</c>. </p> </item> <tag><c>timeout</c></tag> @@ -1126,7 +1201,11 @@ handle_event(_, _, State, Data) -> <seealso marker="#enter_loop/5"><c>enter_loop/5,6</c></seealso>. </p> <p> - It replies to a caller waiting for a reply in + It does not set any + <seealso marker="#type-transition_option"> + <c>transition_option()</c> + </seealso> + but instead 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> @@ -1369,7 +1448,7 @@ handle_event(_, _, State, Data) -> <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>, + and uses a proxy process while <c>{dirty_timeout,<anno>T</anno>}</c> bypasses the proxy process which is more lightweight. </p> @@ -1379,8 +1458,12 @@ handle_event(_, _, State, Data) -> 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? + a late reply. Note that there is an odd chance + to get a late reply even with + <c>{dirty_timeout,infinity}</c> or <c>infinity</c> + for example in the event of network problems. + So why not just let the calling process die + by not catching the exception? </p> </note> <p> @@ -1695,7 +1778,7 @@ handle_event(_, _, State, Data) -> 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 through - <seealso marker="kernel:error_logger#format/2"><c>error_logger:format/2</c></seealso>. + <seealso marker="kernel:logger"><c>logger(3)</c></seealso>. The default <c><anno>Reason</anno></c> is <c>normal</c>. </p> <p> @@ -1891,7 +1974,7 @@ handle_event(_, _, State, Data) -> </p> <note> <p> - Note that if the <c>gen_statem</c> is started trough + Note that if the <c>gen_statem</c> is started through <seealso marker="proc_lib"><c>proc_lib</c></seealso> and <seealso marker="#enter_loop/4"><c>enter_loop/4-6</c></seealso>, @@ -2105,16 +2188,20 @@ init(Args) -> erlang:error(not_implemented, [Args]).</pre> 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 + Note that it is actually allowed to use + <c>{repeat_state, NewData, ...}</c> although it 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. + If you do not update <c>NewData</c> and have some + loop termination condition, or if you use + <c>{repeat_state_and_data, _}</c> or + <c>repeat_state_and_data</c> you have an infinite loop! 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. + <c>keep_state_and_data</c> + since changing states from a <em>state enter call</em> + is not possible anyway. </p> <p> Note the fact that you can use @@ -2199,7 +2286,7 @@ init(Args) -> erlang:error(not_implemented, [Args]).</pre> <c>shutdown</c>, or <c>{shutdown,Term}</c>, the <c>gen_statem</c> 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>. + <seealso marker="kernel:logger"><c>logger(3)</c></seealso>. </p> </desc> </func> diff --git a/lib/stdlib/doc/src/io.xml b/lib/stdlib/doc/src/io.xml index 64fcf4379f..d4a2713840 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>2017</year> + <year>1996</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -137,11 +137,11 @@ Hello world! ok</pre> <p>The general format of a control sequence is <c>~F.P.PadModC</c>.</p> - <p>Character <c>C</c> determines the type of control sequence - to be used, <c>F</c> and <c>P</c> are optional numeric - arguments. If <c>F</c>, <c>P</c>, or <c>Pad</c> is <c>*</c>, - the next argument in <c>Data</c> is used as the numeric value - of <c>F</c> or <c>P</c>.</p> + <p>The character <c>C</c> determines the type of control sequence + to be used. It is the only required field. All of <c>F</c>, + <c>P</c>, <c>Pad</c>, and <c>Mod</c> are optional. For example, + to use a <c>#</c> for <c>Pad</c> but use the default values for + <c>F</c> and <c>P</c>, you can write <c>~..#C</c>.</p> <list type="bulleted"> <item> <p><c>F</c> is the <c>field width</c> of the printed argument. A @@ -167,13 +167,26 @@ ok</pre> The default padding character is <c>' '</c> (space).</p> </item> <item> - <p><c>Mod</c> is the control sequence modifier. It is either a - single character (<c>t</c>, for Unicode - translation, and <c>l</c>, for stopping <c>p</c> and - <c>P</c> from detecting printable characters) - that changes the interpretation of <c>Data</c>.</p> + <p><c>Mod</c> is the control sequence modifier. This is + one or more characters that change the interpretation of + <c>Data</c>. The current modifiers are <c>t</c>, for Unicode + translation, and <c>l</c>, for stopping <c>p</c> and <c>P</c> + from detecting printable characters.</p> </item> </list> + <p>If <c>F</c>, <c>P</c>, or <c>Pad</c> is a <c>*</c> character, + the next argument in <c>Data</c> is used as the value. + For example:</p> + <pre> +1> <input>io:fwrite("~*.*.0f~n",[9, 5, 3.14159265]).</input> +003.14159 +ok</pre> + <p>To use a literal <c>*</c> character as <c>Pad</c>, it must be + passed as an argument:</p> + <pre> +2> <input>io:fwrite("~*.*.*f~n",[9, 5, $*, 3.14159265]).</input> +**3.14159 +ok</pre> <p><em>Available control sequences:</em></p> <taglist> <tag><c>~</c></tag> @@ -257,8 +270,9 @@ ok</pre> \x{400} ok 5> <input>io:fwrite("~s~n",[[1024]]).</input> -** exception exit: {badarg,[{io,format,[<0.26.0>,"~s~n",[[1024]]]}, - ...</pre> +** exception error: bad argument + in function io:format/3 + called as io:format(<0.53.0>,"~s~n",[[1024]])</pre> </item> <tag><c>w</c></tag> <item> @@ -276,10 +290,9 @@ ok <c>~w</c>, but breaks terms whose printed representation is longer than one line into many lines and indents each line sensibly. Left-justification is not supported. - It also tries to detect lists of - printable characters and to output these as strings. The - Unicode translation modifier is used for determining - what characters are printable, for example:</p> + It also tries to detect flat lists of + printable characters and output these as strings. + For example:</p> <pre> 1> <input>T = [{attributes,[[{id,age,1.50000},{mode,explicit},</input> <input>{typename,"INTEGER"}], [{id,cho},{mode,explicit},{typename,'Cho'}]]},</input> @@ -301,7 +314,7 @@ ok {mode,implicit}] ok</pre> <p>The field width specifies the maximum line length. - Defaults to 80. The precision specifies the initial + It defaults to 80. The precision specifies the initial indentation of the term. It defaults to the number of characters printed on this line in the <em>same</em> call to <seealso marker="#write/1"><c>write/1</c></seealso> or @@ -319,11 +332,22 @@ Here T = [{attributes,[[{id,age,1.5}, {tag,{'PRIVATE',3}}, {mode,implicit}] ok</pre> + + <p>As from Erlang/OTP 21.0, a field width of value + <c>0</c> can be used for specifying that a line is + infinitely long, which means that no line breaks + are inserted. For example:</p> + + <pre> +5> <input>io:fwrite("~0p~n", [lists:seq(1, 30)]).</input> +[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30] +ok</pre> + <p>When the modifier <c>l</c> is specified, no detection of printable character lists takes place, for example:</p> <pre> -5> <input>S = [{a,"a"}, {b, "b"}].</input> -6> <input>io:fwrite("~15p~n", [S]).</input> +6> <input>S = [{a,"a"}, {b, "b"}], + io:fwrite("~15p~n", [S]).</input> [{a,"a"}, {b,"b"}] ok @@ -331,18 +355,53 @@ ok [{a,[97]}, {b,[98]}] ok</pre> - <p>Binaries that look like UTF-8 encoded strings are - output with the string syntax if the Unicode translation - modifier is specified:</p> + <p>The Unicode translation modifier <c>t</c> specifies how to treat + characters outside the Latin-1 range of codepoints, in + atoms, strings, and binaries. For example, printing an atom + containing a character > 255:</p> + <pre> +8> <input>io:fwrite("~p~n",[list_to_atom([1024])]).</input> +'\x{400}' +ok +9> <input>io:fwrite("~tp~n",[list_to_atom([1024])]).</input> +'Ѐ' +ok</pre> + <p>By default, Erlang only detects lists of characters + in the Latin-1 range as strings, but the <c>+pc unicode</c> + flag can be used to change this (see <seealso + marker="#printable_range/0"> + <c>printable_range/0</c></seealso> for details). For example:</p> <pre> -9> <input>io:fwrite("~p~n",[[1024]]).</input> +10> <input>io:fwrite("~p~n",[[214]]).</input> +"Ö" +ok +11> <input>io:fwrite("~p~n",[[1024]]).</input> +[1024] +ok +12> <input>io:fwrite("~tp~n",[[1024]]).</input> +[1024] +ok +</pre> + <p>but if Erlang was started with <c>+pc unicode</c>:</p> + <pre> +13> <input>io:fwrite("~p~n",[[1024]]).</input> [1024] -10> <input>io:fwrite("~tp~n",[[1024]]).</input> -"\x{400}" -11> <input>io:fwrite("~tp~n", [<<128,128>>]).</input> +ok +14> <input>io:fwrite("~tp~n",[[1024]]).</input> +"Ѐ" +ok</pre> + <p>Similarly, binaries that look like UTF-8 encoded strings + are output with the binary string syntax if the <c>t</c> + modifier is specified:</p> + <pre> +15> <input>io:fwrite("~p~n", [<<208,128>>]).</input> +<<208,128>> +ok +16> <input>io:fwrite("~tp~n", [<<208,128>>]).</input> +<<"Ѐ"/utf8>> +ok +17> <input>io:fwrite("~tp~n", [<<128,128>>]).</input> <<128,128>> -12> <input>io:fwrite("~tp~n", [<<208,128>>]).</input> -<<"\x{400}"/utf8>> ok</pre> </item> <tag><c>W</c></tag> @@ -454,12 +513,9 @@ ok</pre> abc def 'abc def' {foo,1} A ok 2> <input>io:fwrite("~s", [65]).</input> -** exception exit: {badarg,[{io,format,[<0.22.0>,"~s","A"]}, - {erl_eval,do_apply,5}, - {shell,exprs,6}, - {shell,eval_exprs,6}, - {shell,eval_loop,3}]} - in function io:o_request/2</pre> +** exception error: bad argument + in function io:format/3 + called as io:format(<0.53.0>,"~s","A")</pre> <p>In this example, an attempt was made to output the single character 65 with the aid of the string formatting directive <c>"~s"</c>.</p> diff --git a/lib/stdlib/doc/src/io_lib.xml b/lib/stdlib/doc/src/io_lib.xml index bc1d77ac83..a3df2897ac 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>2017</year> + <year>1996</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -52,6 +52,9 @@ </desc> </datatype> <datatype> + <name name="chars_limit"/> + </datatype> + <datatype> <name name="depth"/> </datatype> <datatype> @@ -153,6 +156,31 @@ </func> <func> + <name name="format" arity="3"/> + <name name="fwrite" arity="3"/> + <fsummary>Write formatted output.</fsummary> + <desc> + <p>Returns a character list that represents <c><anno>Data</anno></c> + formatted in accordance with <c><anno>Format</anno></c> in + the same way as + <seealso marker="#fwrite/2"><c>fwrite/2</c></seealso> and + <seealso marker="#format/2"><c>format/2</c></seealso>, + but takes an extra argument, a list of options.</p> + <p>Valid option:</p> + <taglist> + <tag><c>{chars_limit, <anno>CharsLimit</anno>}</c></tag> + <item> + <p>A soft limit on the number of characters returned. + When the number of characters is reached, remaining + structures are replaced by "<c>...</c>". + <c><anno>CharsLimit</anno></c> defaults to -1, which + means no limit on the number of characters returned.</p> + </item> + </taglist> + </desc> + </func> + + <func> <name name="fread" arity="2"/> <fsummary>Read formatted input.</fsummary> <desc> @@ -361,17 +389,24 @@ <fsummary>Write a term.</fsummary> <desc> <p>Returns a character list that represents <c><anno>Term</anno></c>. - Argument <c><anno>Depth</anno></c> controls the depth of the + Option <c><anno>Depth</anno></c> controls the depth of the structures written. When the specified depth is reached, everything below this level is replaced by "<c>...</c>". <c><anno>Depth</anno></c> defaults to -1, which means - no limitation.</p> + no limitation. Option <c><anno>CharsLimit</anno></c> puts a + soft limit on the number of characters returned. When the + number of characters is reached, remaining structures are + replaced by "<c>...</c>". <c><anno>CharsLimit</anno></c> + defaults to -1, which means no limit on the number of + characters returned.</p> <p><em>Example:</em></p> <pre> 1> <input>lists:flatten(io_lib:write({1,[2],[3],[4,5],6,7,8,9})).</input> "{1,[2],[3],[4,5],6,7,8,9}" 2> <input>lists:flatten(io_lib:write({1,[2],[3],[4,5],6,7,8,9}, 5)).</input> -"{1,[2],[3],[...],...}"</pre> +"{1,[2],[3],[...],...}" +3> <input>lists:flatten(io_lib:write({[1,2,3],[4,5],6,7,8,9}, [{chars_limit,20}])).</input> +"{[1,2|...],[4|...],...}"</pre> </desc> </func> diff --git a/lib/stdlib/doc/src/lib.xml b/lib/stdlib/doc/src/lib.xml deleted file mode 100644 index 58dad7c9e0..0000000000 --- a/lib/stdlib/doc/src/lib.xml +++ /dev/null @@ -1,103 +0,0 @@ -<?xml version="1.0" encoding="utf-8" ?> -<!DOCTYPE erlref SYSTEM "erlref.dtd"> - -<erlref> - <header> - <copyright> - <year>1996</year><year>2016</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 - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. - - </legalnotice> - - <title>lib</title> - <prepared></prepared> - <docno></docno> - <date></date> - <rev></rev> - </header> - <module>lib</module> - <modulesummary>Useful library functions.</modulesummary> - <description> - <warning> - <p>This module is retained for backward compatibility. It can disappear - without warning in a future Erlang/OTP release.</p> - </warning> - </description> - - <funcs> - <func> - <name name="error_message" arity="2"/> - <fsummary>Print error message.</fsummary> - <desc> - <p>Prints error message <c><anno>Args</anno></c> in accordance with - <c><anno>Format</anno></c>. Similar to - <seealso marker="io#format/1"><c>io:format/2</c></seealso>.</p> - </desc> - </func> - - <func> - <name name="flush_receive" arity="0"/> - <fsummary>Flush messages.</fsummary> - <desc> - <p>Flushes the message buffer of the current process.</p> - </desc> - </func> - - <func> - <name name="nonl" arity="1"/> - <fsummary>Remove last newline.</fsummary> - <desc> - <p>Removes the last newline character, if any, in - <c><anno>String1</anno></c>.</p> - </desc> - </func> - - <func> - <name name="progname" arity="0"/> - <fsummary>Return name of Erlang start script.</fsummary> - <desc> - <p>Returns the name of the script that started the current - Erlang session.</p> - </desc> - </func> - - <func> - <name name="send" arity="2"/> - <fsummary>Send a message.</fsummary> - <desc> - <p>Makes it possible to send a message using the <c>apply/3</c> BIF.</p> - </desc> - </func> - - <func> - <name name="sendw" arity="2"/> - <fsummary>Send a message and wait for an answer.</fsummary> - <desc> - <p>As <seealso marker="#send/2"><c>send/2</c></seealso>, - but waits for an answer. It is implemented as follows:</p> - <code type="none"> -sendw(To, Msg) -> - To ! {self(),Msg}, - receive - Reply -> Reply - end.</code> - <p>The returned message is not necessarily a reply to the sent - message.</p> - </desc> - </func> - </funcs> -</erlref> - diff --git a/lib/stdlib/doc/src/lists.xml b/lib/stdlib/doc/src/lists.xml index 7efafedc82..c3d5d7e07a 100644 --- a/lib/stdlib/doc/src/lists.xml +++ b/lib/stdlib/doc/src/lists.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2017</year> + <year>1996</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -771,6 +771,18 @@ length(lists:seq(From, To, Incr)) =:= (To - From + Incr) div Incr</code> </func> <func> + <name name="search" arity="2"/> + <fsummary>Find the first element that satisfies a predicate.</fsummary> + <desc> + <p>If there is a <c><anno>Value</anno></c> in <c><anno>List</anno></c> + such that <c><anno>Pred</anno>(<anno>Value</anno>)</c> returns + <c>true</c>, returns <c>{value, <anno>Value</anno>}</c> + for the first such <c><anno>Value</anno></c>, + otherwise returns <c>false</c>.</p> + </desc> + </func> + + <func> <name name="splitwith" arity="2"/> <fsummary>Split a list into two lists based on a predicate.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/maps.xml b/lib/stdlib/doc/src/maps.xml index 8c7270816b..987d92989d 100644 --- a/lib/stdlib/doc/src/maps.xml +++ b/lib/stdlib/doc/src/maps.xml @@ -33,16 +33,31 @@ <p>This module contains functions for maps processing.</p> </description> + <datatypes> + <datatype> + <name name="iterator"/> + <desc> + <p>An iterator representing the key value associations in a map.</p> + <p>Created using <seealso marker="#iterator-1"><c>maps:iterator/1</c></seealso>.</p> + <p>Consumed by <seealso marker="#next-1"><c>maps:next/1</c></seealso>, + <seealso marker="#filter-2"><c>maps:filter/2</c></seealso>, + <seealso marker="#fold-3"><c>maps:fold/3</c></seealso> and + <seealso marker="#map-2"><c>maps:map/2</c></seealso>.</p> + </desc> + </datatype> + </datatypes> + <funcs> <func> <name name="filter" arity="2"/> <fsummary>Select pairs that satisfy a predicate.</fsummary> <desc> - <p>Returns a map <c><anno>Map2</anno></c> for which predicate - <c><anno>Pred</anno></c> holds true in <c><anno>Map1</anno></c>.</p> + <p>Returns a map <c><anno>Map</anno></c> for which predicate + <c><anno>Pred</anno></c> holds true in <c><anno>MapOrIter</anno></c>.</p> <p>The call fails with a <c>{badmap,Map}</c> exception if - <c><anno>Map1</anno></c> is not a map, or with <c>badarg</c> if - <c><anno>Pred</anno></c> is not a function of arity 2.</p> + <c><anno>MapOrIter</anno></c> is not a map or valid iterator, + or with <c>badarg</c> if <c><anno>Pred</anno></c> is not a + function of arity 2.</p> <p><em>Example:</em></p> <code type="none"> > M = #{a => 2, b => 3, c=> 4, "a" => 1, "b" => 2, "c" => 4}, @@ -76,12 +91,16 @@ <fsummary></fsummary> <desc> <p>Calls <c>F(K, V, AccIn)</c> for every <c><anno>K</anno></c> to value - <c><anno>V</anno></c> association in <c><anno>Map</anno></c> in + <c><anno>V</anno></c> association in <c><anno>MapOrIter</anno></c> in any order. Function <c>fun F/3</c> must return a new accumulator, which is passed to the next successive call. This function returns the final value of the accumulator. The initial accumulator value <c><anno>Init</anno></c> is returned if the map is empty.</p> + <p>The call fails with a <c>{badmap,Map}</c> exception if + <c><anno>MapOrIter</anno></c> is not a map or valid iterator, + or with <c>badarg</c> if <c><anno>Fun</anno></c> is not a + function of arity 3.</p> <p><em>Example:</em></p> <code type="none"> > Fun = fun(K,V,AccIn) when is_list(K) -> AccIn + V end, @@ -169,6 +188,32 @@ false</code> </func> <func> + <name name="iterator" arity="1"/> + <fsummary>Create a map iterator.</fsummary> + <desc> + <p>Returns a map iterator <c><anno>Iterator</anno></c> that can + be used by <seealso marker="#next-1"><c>maps:next/1</c></seealso> + to traverse the key-value associations in a map. When iterating + over a map, the memory usage is guaranteed to be bounded no matter + the size of the map.</p> + <p>The call fails with a <c>{badmap,Map}</c> exception if + <c><anno>Map</anno></c> is not a map.</p> + <p><em>Example:</em></p> + <code type="none"> +> M = #{ a => 1, b => 2 }. +#{a => 1,b => 2} +> I = maps:iterator(M). +[{a,1},{b,2}] +> {K1, V1, I2} = maps:next(I). +{a,1,[{b,2}]} +> {K2, V2, I3} = maps:next(I2). +{b,2,[]} +> maps:next(I3). +none</code> + </desc> + </func> + + <func> <name name="keys" arity="1"/> <fsummary></fsummary> <desc> @@ -188,12 +233,16 @@ false</code> <name name="map" arity="2"/> <fsummary></fsummary> <desc> - <p>Produces a new map <c><anno>Map2</anno></c> by calling function + <p>Produces a new map <c><anno>Map</anno></c> by calling function <c>fun F(K, V1)</c> for every <c><anno>K</anno></c> to value - <c><anno>V1</anno></c> association in <c><anno>Map1</anno></c> in + <c><anno>V1</anno></c> association in <c><anno>MapOrIter</anno></c> in any order. Function <c>fun F/2</c> must return value <c><anno>V2</anno></c> to be associated with key <c><anno>K</anno></c> - for the new map <c><anno>Map2</anno></c>.</p> + for the new map <c><anno>Map</anno></c>.</p> + <p>The call fails with a <c>{badmap,Map}</c> exception if + <c><anno>MapOrIter</anno></c> is not a map or valid iterator, + or with <c>badarg</c> if <c><anno>Fun</anno></c> is not a + function of arity 2.</p> <p><em>Example:</em></p> <code type="none"> > Fun = fun(K,V1) when is_list(K) -> V1*2 end, @@ -234,6 +283,35 @@ false</code> </func> <func> + <name name="next" arity="1"/> + <fsummary>Get the next key and value from an iterator.</fsummary> + <desc> + <p>Returns the next key-value association in + <c><anno>Iterator</anno></c> and a new iterator for the + remaining associations in the iterator. + </p> + <p> + If there are no more associations in the iterator, + <c>none</c> is returned. + </p> + <p><em>Example:</em></p> + <code type="none"> +> Map = #{a => 1, b => 2, c => 3}. +#{a => 1,b => 2,c => 3} +> Iter = maps:iterator(Map). +[{a,1},{b,2},{c,3}] +> {_, _, Iter1} = maps:next(Iter). +{a,1,[{b,2},{c,3}]} +> {_, _, Iter2} = maps:next(Iter1). +{b,2,[{c,3}]} +> {_, _, Iter3} = maps:next(Iter2). +{c,3,[]} +> maps:next(Iter3). +none</code> + </desc> + </func> + + <func> <name name="put" arity="3"/> <fsummary></fsummary> <desc> diff --git a/lib/stdlib/doc/src/ordsets.xml b/lib/stdlib/doc/src/ordsets.xml index 7b590932e4..2d891d7a5a 100644 --- a/lib/stdlib/doc/src/ordsets.xml +++ b/lib/stdlib/doc/src/ordsets.xml @@ -142,6 +142,15 @@ </func> <func> + <name name="is_empty" arity="1"/> + <fsummary>Test for empty set.</fsummary> + <desc> + <p>Returns <c>true</c> if <c><anno>Ordset</anno></c> is an empty set, + otherwise <c>false</c>.</p> + </desc> + </func> + + <func> <name name="is_set" arity="1"/> <fsummary>Test for an <c>Ordset</c>.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/proc_lib.xml b/lib/stdlib/doc/src/proc_lib.xml index cb152d1935..51380ae51c 100644 --- a/lib/stdlib/doc/src/proc_lib.xml +++ b/lib/stdlib/doc/src/proc_lib.xml @@ -59,18 +59,17 @@ <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 SASL - event handler. That is, the crash report is normally only visible - if the SASL application is started; see - <seealso marker="sasl:sasl_app"><c>sasl(6)</c></seealso> and section + is generated, which is written to terminal by the default logger + handler setup by Kernel. For more information about how crash reports + were logged prior to Erlang/OTP 21.0, see <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 + emulator. All exceptions are converted to <em>exits</em> which are ignored by the default - <c>error_logger</c> handler.</p> + <c>logger</c> handler.</p> <p>The crash report contains the previously stored information, such as ancestors and initial function, the termination reason, and @@ -115,12 +114,22 @@ <name name="format" arity="2"/> <fsummary>Format a crash report.</fsummary> <desc> - <p>This function can be used by a user-defined event handler to + <note> + <p>This function is deprecated in the sense that + the <c>error_logger</c> is no longer the preferred + interface for logging in Erlang/OTP. A + new <seealso marker="kernel:logger_chapter">logging + API</seealso> was added in Erlang/OTP 21.0, but + legacy <c>error_logger</c> handlers can still be used. New + Logger handlers do not need to use this function, since + the formatting callback (<c>report_cb</c>) is included as + metadata in the log event.</p> + </note> + <p>This function can be used by a user-defined legacy + <c>error_logger</c> event handler to format a crash report. The crash report is sent using - <seealso marker="kernel:error_logger#error_report/2"> - <c>error_logger:error_report(crash_report, - <anno>CrashReport</anno>)</c></seealso>. - That is, the event to be handled is of the format + <seealso marker="kernel:logger"> + <c>logger(3)</c></seealso>, and the event to be handled is of the format <c>{error_report, GL, {Pid, crash_report, <anno>CrashReport</anno>}}</c>, where <c>GL</c> is the group leader pid of process @@ -132,7 +141,19 @@ <name name="format" arity="3"/> <fsummary>Format a crash report.</fsummary> <desc> - <p>This function can be used by a user-defined event handler to + <note> + <p>This function is deprecated in the sense that + the <c>error_logger</c> is no longer the preferred + interface for logging in Erlang/OTP. A + new <seealso marker="kernel:logger_chapter">logging + API</seealso> was added in Erlang/OTP 21.0, but + legacy <c>error_logger</c> handlers can still be used. New + Logger handlers do not need to used this function, since + the formatting callback (<c>report_cb</c>) is included as + metadata in the log event.</p> + </note> + <p>This function can be used by a user-defined legacy + <c>error_logger</c> event handler to format a crash report. When <anno>Depth</anno> is specified as a positive integer, it is used in the format string to limit the output as follows: <c>io_lib:format("~P", @@ -395,6 +416,8 @@ init(Parent) -> <title>See Also</title> <p><seealso marker="kernel:error_logger"> <c>error_logger(3)</c></seealso></p> + <p><seealso marker="kernel:logger"> + <c>logger(3)</c></seealso></p> </section> </erlref> diff --git a/lib/stdlib/doc/src/rand.xml b/lib/stdlib/doc/src/rand.xml index 89fb858823..21f680a0ee 100644 --- a/lib/stdlib/doc/src/rand.xml +++ b/lib/stdlib/doc/src/rand.xml @@ -133,8 +133,9 @@ variable <c>rand_seed</c> to remember the current state.</p> <p>If a process calls - <seealso marker="#uniform-0"><c>uniform/0</c></seealso> or - <seealso marker="#uniform-1"><c>uniform/1</c></seealso> without + <seealso marker="#uniform-0"><c>uniform/0</c></seealso>, + <seealso marker="#uniform-1"><c>uniform/1</c></seealso> or + <seealso marker="#uniform_real-0"><c>uniform_real/0</c></seealso> without setting a seed first, <seealso marker="#seed-1"><c>seed/1</c></seealso> is called automatically with the default algorithm and creates a non-constant seed.</p> @@ -168,10 +169,17 @@ R3 = rand:uniform(),</pre> S0 = rand:seed_s(exrop), {R4, S1} = rand:uniform_s(S0),</pre> + <p>Textbook basic form Box-Muller standard normal deviate</p> + + <pre> +R5 = rand:uniform_real(), +R6 = rand:uniform(), +SND0 = math:sqrt(-2 * math:log(R5)) * math:cos(math:pi() * R6)</pre> + <p>Create a standard normal deviate:</p> <pre> -{SND0, S2} = rand:normal_s(S1),</pre> +{SND1, S2} = rand:normal_s(S1),</pre> <p>Create a normal deviate with mean -3 and variance 0.5:</p> @@ -414,7 +422,8 @@ tests. We suggest to use a sign test to extract a random Boolean value.</pre> This function may return exactly <c>0.0</c> which can be fatal for certain applications. If that is undesired you can use <c>(1.0 - rand:uniform())</c> to get the - interval <c>0.0 < <anno>X</anno> =< 1.0</c>. + interval <c>0.0 < <anno>X</anno> =< 1.0</c>, or instead use + <seealso marker="#uniform_real-0"><c>uniform_real/0</c></seealso>. </p> <p> If neither endpoint is desired you can test and re-try @@ -432,6 +441,42 @@ end.</pre> </func> <func> + <name name="uniform_real" arity="0"/> + <fsummary>Return a random float.</fsummary> + <desc><marker id="uniform_real-0"/> + <p> + Returns a random float + uniformly distributed in the value range + <c>DBL_MIN =< <anno>X</anno> < 1.0</c> + and updates the state in the process dictionary. + </p> + <p> + Conceptually, a random real number <c>R</c> is generated + from the interval <c>0 =< R < 1</c> and then the + closest rounded down normalized number + in the IEEE 754 Double precision format + is returned. + </p> + <note> + <p> + The generated numbers from this function has got better + granularity for small numbers than the regular + <seealso marker="#uniform-0"><c>uniform/0</c></seealso> + because all bits in the mantissa are random. + This property, in combination with the fact that exactly zero + is never returned is useful for algoritms doing for example + <c>1.0 / <anno>X</anno></c> or <c>math:log(<anno>X</anno>)</c>. + </p> + </note> + <p> + See + <seealso marker="#uniform_real_s-1"><c>uniform_real_s/1</c></seealso> + for more explanation. + </p> + </desc> + </func> + + <func> <name name="uniform" arity="1"/> <fsummary>Return a random integer.</fsummary> <desc><marker id="uniform-1"/> @@ -460,7 +505,8 @@ end.</pre> This function may return exactly <c>0.0</c> which can be fatal for certain applications. If that is undesired you can use <c>(1.0 - rand:uniform(State))</c> to get the - interval <c>0.0 < <anno>X</anno> =< 1.0</c>. + interval <c>0.0 < <anno>X</anno> =< 1.0</c>, or instead use + <seealso marker="#uniform_real_s-1"><c>uniform_real_s/1</c></seealso>. </p> <p> If neither endpoint is desired you can test and re-try @@ -478,6 +524,68 @@ end.</pre> </func> <func> + <name name="uniform_real_s" arity="1"/> + <fsummary>Return a random float.</fsummary> + <desc> + <p> + Returns, for a specified state, a random float + uniformly distributed in the value range + <c>DBL_MIN =< <anno>X</anno> < 1.0</c> + and updates the state in the process dictionary. + </p> + <p> + Conceptually, a random real number <c>R</c> is generated + from the interval <c>0 =< R < 1</c> and then the + closest rounded down normalized number + in the IEEE 754 Double precision format + is returned. + </p> + <note> + <p> + The generated numbers from this function has got better + granularity for small numbers than the regular + <seealso marker="#uniform_s-1"><c>uniform_s/1</c></seealso> + because all bits in the mantissa are random. + This property, in combination with the fact that exactly zero + is never returned is useful for algoritms doing for example + <c>1.0 / <anno>X</anno></c> or <c>math:log(<anno>X</anno>)</c>. + </p> + </note> + <p> + The concept implicates that the probability to get + exactly zero is extremely low; so low that this function + is in fact guaranteed to never return zero. The smallest + number that it might return is <c>DBL_MIN</c>, which is + 2.0^(-1022). + </p> + <p> + The value range stated at the top of this function + description is technically correct, but + <c>0.0 =< <anno>X</anno> < 1.0</c> + is a better description of the generated numbers' + statistical distribution. Except that exactly 0.0 + is never returned, which is not possible to observe + statistically. + </p> + <p> + For example; for all sub ranges + <c>N*2.0^(-53) =< X < (N+1)*2.0^(-53)</c> + where + <c>0 =< integer(N) < 2.0^53</c> + the probability is the same. + Compare that with the form of the numbers generated by + <seealso marker="#uniform_s-1"><c>uniform_s/1</c></seealso>. + </p> + <p> + Having to generate extra random bits for + small numbers costs a little performance. + This function is about 20% slower than the regular + <seealso marker="#uniform_s-1"><c>uniform_s/1</c></seealso> + </p> + </desc> + </func> + + <func> <name name="uniform_s" arity="2"/> <fsummary>Return a random integer.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/ref_man.xml b/lib/stdlib/doc/src/ref_man.xml index 878a3babc5..c6f30d272d 100644 --- a/lib/stdlib/doc/src/ref_man.xml +++ b/lib/stdlib/doc/src/ref_man.xml @@ -66,7 +66,6 @@ <xi:include href="gen_statem.xml"/> <xi:include href="io.xml"/> <xi:include href="io_lib.xml"/> - <xi:include href="lib.xml"/> <xi:include href="lists.xml"/> <xi:include href="log_mf_h.xml"/> <xi:include href="maps.xml"/> @@ -93,6 +92,7 @@ <xi:include href="sys.xml"/> <xi:include href="timer.xml"/> <xi:include href="unicode.xml"/> + <xi:include href="uri_string.xml"/> <xi:include href="win32reg.xml"/> <xi:include href="zip.xml"/> </application> diff --git a/lib/stdlib/doc/src/sets.xml b/lib/stdlib/doc/src/sets.xml index 4934bed365..1ed96ddc3f 100644 --- a/lib/stdlib/doc/src/sets.xml +++ b/lib/stdlib/doc/src/sets.xml @@ -140,6 +140,15 @@ </func> <func> + <name name="is_empty" arity="1"/> + <fsummary>Test for empty set.</fsummary> + <desc> + <p>Returns <c>true</c> if <c><anno>Set</anno></c> is an empty set, + otherwise <c>false</c>.</p> + </desc> + </func> + + <func> <name name="is_set" arity="1"/> <fsummary>Test for a <c>Set</c>.</fsummary> <desc> diff --git a/lib/stdlib/doc/src/specs.xml b/lib/stdlib/doc/src/specs.xml index 45b207b13d..fd2d625685 100644 --- a/lib/stdlib/doc/src/specs.xml +++ b/lib/stdlib/doc/src/specs.xml @@ -33,7 +33,6 @@ <xi:include href="../specs/specs_gen_statem.xml"/> <xi:include href="../specs/specs_io.xml"/> <xi:include href="../specs/specs_io_lib.xml"/> - <xi:include href="../specs/specs_lib.xml"/> <xi:include href="../specs/specs_lists.xml"/> <xi:include href="../specs/specs_log_mf_h.xml"/> <xi:include href="../specs/specs_maps.xml"/> @@ -60,6 +59,7 @@ <xi:include href="../specs/specs_sys.xml"/> <xi:include href="../specs/specs_timer.xml"/> <xi:include href="../specs/specs_unicode.xml"/> + <xi:include href="../specs/specs_uri_string.xml"/> <xi:include href="../specs/specs_win32reg.xml"/> <xi:include href="../specs/specs_zip.xml"/> </specs> diff --git a/lib/stdlib/doc/src/string.xml b/lib/stdlib/doc/src/string.xml index 9d5edd9ecf..4a3d37dcb6 100644 --- a/lib/stdlib/doc/src/string.xml +++ b/lib/stdlib/doc/src/string.xml @@ -111,8 +111,8 @@ <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. + are still available but should not be used, they will be + deprecated in a future release. </p> </description> @@ -594,7 +594,7 @@ ÖÄÅ</pre> 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 + <p> Default <c><anno>Characters</anno></c> is the set of nonbreakable whitespace codepoints, defined as Pattern_White_Space in <url href="http://unicode.org/reports/tr31/">Unicode Standard Annex #31</url>. @@ -641,7 +641,7 @@ ÖÄÅ</pre> <note><p> The functions are kept for backward compatibility, but are not recommended. - They will be deprecated in Erlang/OTP 21. + They will be deprecated in a future release. </p> <p>Any undocumented functions in <c>string</c> are not to be used.</p> </note> diff --git a/lib/stdlib/doc/src/sys.xml b/lib/stdlib/doc/src/sys.xml index 64d8789016..59e5bb6cb5 100644 --- a/lib/stdlib/doc/src/sys.xml +++ b/lib/stdlib/doc/src/sys.xml @@ -102,7 +102,7 @@ then treated in the debug function. For example, <c>trace</c> formats the system events to the terminal. </p> - <p>Three predefined system events are used when a + <p>Four predefined system events are used when a process receives or sends a message. The process can also define its own system events. It is always up to the process itself to format these events.</p> @@ -276,7 +276,9 @@ <p><c><anno>Func</anno></c> is called whenever a system event is generated. This function is to return <c>done</c>, or a new <c>Func</c> state. In the first case, the function is removed. It is - also removed if the function fails.</p> + also removed if the function fails. If one debug function should be + installed more times, a unique <c><anno>FuncId</anno></c> must be + specified for each installation.</p> </desc> </func> @@ -330,8 +332,8 @@ <fsummary>Remove a debug function from the process.</fsummary> <desc> <p>Removes an installed debug function from the - process. <c><anno>Func</anno></c> must be the same as previously - installed.</p> + process. <c><anno>Func</anno></c> or <c><anno>FuncId</anno></c> must be + the same as previously installed.</p> </desc> </func> diff --git a/lib/stdlib/doc/src/timer.xml b/lib/stdlib/doc/src/timer.xml index 350847bf7d..53107ade2c 100644 --- a/lib/stdlib/doc/src/timer.xml +++ b/lib/stdlib/doc/src/timer.xml @@ -270,8 +270,8 @@ <item> <p>Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>, <anno>Arguments</anno>)</c> and measures the elapsed real time as - reported by <seealso marker="kernel:os#timestamp/0"> - <c>os:timestamp/0</c></seealso>.</p> + reported by <seealso marker="erts:erlang#monotonic_time/0"> + <c>erlang:monotonic_time/0</c></seealso>.</p> <p>Returns <c>{<anno>Time</anno>, <anno>Value</anno>}</c>, where <c><anno>Time</anno></c> is the elapsed real time in <em>microseconds</em>, and <c><anno>Value</anno></c> is what is diff --git a/lib/stdlib/doc/src/unicode_usage.xml b/lib/stdlib/doc/src/unicode_usage.xml index 26dc46719e..789e063c12 100644 --- a/lib/stdlib/doc/src/unicode_usage.xml +++ b/lib/stdlib/doc/src/unicode_usage.xml @@ -719,8 +719,8 @@ Eshell V5.10.1 (abort with ^G) </section> <section> - <title>Unicode Filenames</title> <marker id="unicode_file_names"/> + <title>Unicode Filenames</title> <p>Most modern operating systems support Unicode filenames in some way. There are many different ways to do this and Erlang by default treats the different approaches differently:</p> @@ -855,8 +855,12 @@ Eshell V5.10.1 (abort with ^G) </note> <section> - <title>Notes About Raw Filenames</title> <marker id="notes-about-raw-filenames"/> + <title>Notes About Raw Filenames</title> + <note><p> + Note that raw filenames <em>not</em> necessarily are encoded the + same way as on the OS level. + </p></note> <p>Raw filenames were introduced together with Unicode filename support in ERTS 5.8.2 (Erlang/OTP R14B01). The reason "raw filenames" were introduced in the system was diff --git a/lib/stdlib/doc/src/uri_string.xml b/lib/stdlib/doc/src/uri_string.xml new file mode 100644 index 0000000000..88d4600611 --- /dev/null +++ b/lib/stdlib/doc/src/uri_string.xml @@ -0,0 +1,359 @@ +<?xml version="1.0" encoding="utf-8" ?> +<!DOCTYPE erlref SYSTEM "erlref.dtd"> + +<erlref> + <header> + <copyright> + <year>2017</year><year>2018</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 + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. + </legalnotice> + + <title>uri_string</title> + <prepared>Péter Dimitrov</prepared> + <docno>1</docno> + <date>2018-02-07</date> + <rev>A</rev> + </header> + <module>uri_string</module> + <modulesummary>URI processing functions.</modulesummary> + <description> + <p>This module contains functions for parsing and handling URIs + (<url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url>) and + form-urlencoded query strings (<url href="https://www.w3.org/TR/html52/">HTML 5.2</url>). + </p> + <p> + Parsing and serializing non-UTF-8 form-urlencoded query strings are also supported + (<url href="https://www.w3.org/TR/html50/">HTML 5.0</url>). + </p> + <p>A URI is an identifier consisting of a sequence of characters matching the syntax + rule named <em>URI</em> in <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url>. + </p> + <p> The generic URI syntax consists of a hierarchical sequence of components referred + to as the scheme, authority, path, query, and fragment:</p> + <pre> + URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ] + hier-part = "//" authority path-abempty + / path-absolute + / path-rootless + / path-empty + scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." ) + authority = [ userinfo "@" ] host [ ":" port ] + userinfo = *( unreserved / pct-encoded / sub-delims / ":" ) + + reserved = gen-delims / sub-delims + gen-delims = ":" / "/" / "?" / "#" / "[" / "]" / "@" + sub-delims = "!" / "$" / "&" / "'" / "(" / ")" + / "*" / "+" / "," / ";" / "=" + + unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~" + </pre><br></br> + <p>The interpretation of a URI depends only on the characters used and not on how those + characters are represented in a network protocol.</p> + <p>The functions implemented by this module cover the following use cases:</p> + <list type="bulleted"> + <item>Parsing URIs into its components and returing a map<br></br> + <seealso marker="#parse/1"><c>parse/1</c></seealso> + </item> + <item>Recomposing a map of URI components into a URI string<br></br> + <seealso marker="#recompose/1"><c>recompose/1</c></seealso> + </item> + <item>Changing inbound binary and percent-encoding of URIs<br></br> + <seealso marker="#transcode/2"><c>transcode/2</c></seealso> + </item> + <item>Transforming URIs into a normalized form<br></br> + <seealso marker="#normalize/1"><c>normalize/1</c></seealso><br></br> + <seealso marker="#normalize/2"><c>normalize/2</c></seealso> + </item> + <item>Composing form-urlencoded query strings from a list of key-value pairs<br></br> + <seealso marker="#compose_query/1"><c>compose_query/1</c></seealso><br></br> + <seealso marker="#compose_query/2"><c>compose_query/2</c></seealso> + </item> + <item>Dissecting form-urlencoded query strings into a list of key-value pairs<br></br> + <seealso marker="#dissect_query/1"><c>dissect_query/1</c></seealso> + </item> + </list> + <p>There are four different encodings present during the handling of URIs:</p> + <list type="bulleted"> + <item>Inbound binary encoding in binaries</item> + <item>Inbound percent-encoding in lists and binaries</item> + <item>Outbound binary encoding in binaries</item> + <item>Outbound percent-encoding in lists and binaries</item> + </list> + <p>Functions with <c>uri_string()</c> argument accept lists, binaries and + mixed lists (lists with binary elements) as input type. All of the functions but + <c>transcode/2</c> expects input as lists of unicode codepoints, UTF-8 encoded binaries + and UTF-8 percent-encoded URI parts ("%C3%B6" corresponds to the unicode character "ö").</p> + <p>Unless otherwise specified the return value type and encoding are the same as the input + type and encoding. That is, binary input returns binary output, list input returns a list + output but mixed input returns list output.</p> + <p>In case of lists there is only percent-encoding. In binaries, however, both binary encoding + and percent-encoding shall be considered. <c>transcode/2</c> provides the means to convert + between the supported encodings, it takes a <c>uri_string()</c> and a list of options + specifying inbound and outbound encodings.</p> + <p><url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url> does not mandate any specific + character encoding and it is usually defined by the protocol or surrounding text. This library + takes the same assumption, binary and percent-encoding are handled as one configuration unit, + they cannot be set to different values.</p> + </description> + + <datatypes> + <datatype> + <name name="error"/> + <desc> + <p>Error tuple indicating the type of error. Possible values of the second component:</p> + <list type="bulleted"> + <item><c>invalid_character</c></item> + <item><c>invalid_encoding</c></item> + <item><c>invalid_input</c></item> + <item><c>invalid_map</c></item> + <item><c>invalid_percent_encoding</c></item> + <item><c>invalid_scheme</c></item> + <item><c>invalid_uri</c></item> + <item><c>invalid_utf8</c></item> + <item><c>missing_value</c></item> + </list> + <p>The third component is a term providing additional information about the + cause of the error.</p> + </desc> + </datatype> + <datatype> + <name name="uri_map"/> + <desc> + <p>Map holding the main components of a URI.</p> + </desc> + </datatype> + <datatype> + <name name="uri_string"/> + <desc> + <p>List of unicode codepoints, a UTF-8 encoded binary, or a mix of the two, + representing an <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url> + compliant URI (<em>percent-encoded form</em>). + A URI is a sequence of characters from a very limited set: the letters of + the basic Latin alphabet, digits, and a few special characters.</p> + </desc> + </datatype> + </datatypes> + + <funcs> + + <func> + <name name="compose_query" arity="1"/> + <fsummary>Compose urlencoded query string.</fsummary> + <desc> + <p>Composes a form-urlencoded <c><anno>QueryString</anno></c> based on a + <c><anno>QueryList</anno></c>, a list of non-percent-encoded key-value pairs. + Form-urlencoding is defined in section + 4.10.21.6 of the <url href="https://www.w3.org/TR/html52/">HTML 5.2</url> + specification and in section 4.10.22.6 of the + <url href="https://www.w3.org/TR/html50/">HTML 5.0</url> specification for + non-UTF-8 encodings. + </p> + <p>See also the opposite operation <seealso marker="#dissect_query/1"> + <c>dissect_query/1</c></seealso>. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>uri_string:compose_query([{"foo bar","1"},{"city","örebro"}]).</input> +<![CDATA["foo+bar=1&city=%C3%B6rebro"]]> +2> <![CDATA[uri_string:compose_query([{<<"foo bar">>,<<"1">>}, +2> {<<"city">>,<<"örebro"/utf8>>}]).]]> +<![CDATA[<<"foo+bar=1&city=%C3%B6rebro">>]]> + </pre> + </desc> + </func> + + <func> + <name name="compose_query" arity="2"/> + <fsummary>Compose urlencoded query string.</fsummary> + <desc> + <p>Same as <c>compose_query/1</c> but with an additional + <c><anno>Options</anno></c> parameter, that controls the encoding ("charset") + used by the encoding algorithm. There are two supported encodings: <c>utf8</c> + (or <c>unicode</c>) and <c>latin1</c>. + </p> + <p>Each character in the entry's name and value that cannot be expressed using + the selected character encoding, is replaced by a string consisting of a U+0026 + AMPERSAND character (<![CDATA[&]]>), a "#" (U+0023) character, one or more ASCII + digits representing the Unicode code point of the character in base ten, and + finally a ";" (U+003B) character. + </p> + <p>Bytes that are out of the range 0x2A, 0x2D, 0x2E, 0x30 to 0x39, 0x41 to 0x5A, 0x5F, + 0x61 to 0x7A, are percent-encoded (U+0025 PERCENT SIGN character (%) followed by + uppercase ASCII hex digits representing the hexadecimal value of the byte). + </p> + <p>See also the opposite operation <seealso marker="#dissect_query/1"> + <c>dissect_query/1</c></seealso>. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>uri_string:compose_query([{"foo bar","1"},{"city","örebro"}],</input> +1> [{encoding, latin1}]). +<![CDATA["foo+bar=1&city=%F6rebro" +2> uri_string:compose_query([{<<"foo bar">>,<<"1">>}, +2> {<<"city">>,<<"東京"/utf8>>}], [{encoding, latin1}]).]]> +<![CDATA[<<"foo+bar=1&city=%26%2326481%3B%26%2320140%3B">>]]> + </pre> + </desc> + </func> + + <func> + <name name="dissect_query" arity="1"/> + <fsummary>Dissect query string.</fsummary> + <desc> + <p>Dissects an urlencoded <c><anno>QueryString</anno></c> and returns a + <c><anno>QueryList</anno></c>, a list of non-percent-encoded key-value pairs. + Form-urlencoding is defined in section + 4.10.21.6 of the <url href="https://www.w3.org/TR/html52/">HTML 5.2</url> + specification and in section 4.10.22.6 of the + <url href="https://www.w3.org/TR/html50/">HTML 5.0</url> specification for + non-UTF-8 encodings. + </p> + <p>See also the opposite operation <seealso marker="#compose_query/1"> + <c>compose_query/1</c></seealso>. + </p> + <p><em>Example:</em></p> + <pre> +1> <input><![CDATA[uri_string:dissect_query("foo+bar=1&city=%C3%B6rebro").]]></input> +[{"foo bar","1"},{"city","örebro"}] +2> <![CDATA[uri_string:dissect_query(<<"foo+bar=1&city=%26%2326481%3B%26%2320140%3B">>).]]> +<![CDATA[[{<<"foo bar">>,<<"1">>}, + {<<"city">>,<<230,157,177,228,186,172>>}] ]]> + </pre> + </desc> + </func> + + <func> + <name name="normalize" arity="1"/> + <fsummary>Syntax-based normalization.</fsummary> + <desc> + <p>Transforms an <c><anno>URI</anno></c> into a normalized form + using Syntax-Based Normalization as defined by + <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url>.</p> + <p>This function implements case normalization, percent-encoding + normalization, path segment normalization and scheme based normalization + for HTTP(S) with basic support for FTP, SSH, SFTP and TFTP.</p> + <p><em>Example:</em></p> + <pre> +1> <input>uri_string:normalize("/a/b/c/./../../g").</input> +"/a/g" +2> <![CDATA[uri_string:normalize(<<"mid/content=5/../6">>).]]> +<![CDATA[<<"mid/6">>]]> +3> uri_string:normalize("http://localhost:80"). +"https://localhost/" +4> <input>uri_string:normalize(#{scheme => "http",port => 80,path => "/a/b/c/./../../g",</input> +4> host => "localhost-örebro"}). +"http://localhost-%C3%B6rebro/a/g" + </pre> + </desc> + </func> + + <func> + <name name="normalize" arity="2"/> + <fsummary>Syntax-based normalization.</fsummary> + <desc> + <p>Same as <c>normalize/1</c> but with an additional + <c><anno>Options</anno></c> parameter, that controls if the normalized URI + shall be returned as an uri_map(). + There is one supported option: <c>return_map</c>. + </p> + <p><em>Example:</em></p> + <pre> +1> <input>uri_string:normalize("/a/b/c/./../../g", [return_map]).</input> +#{path => "/a/g"} +2> <![CDATA[uri_string:normalize(<<"mid/content=5/../6">>, [return_map]).]]> +<![CDATA[#{path => <<"mid/6">>}]]> +3> uri_string:normalize("http://localhost:80", [return_map]). +#{scheme => "http",path => "/",host => "localhost"} +4> <input>uri_string:normalize(#{scheme => "http",port => 80,path => "/a/b/c/./../../g",</input> +4> host => "localhost-örebro"}, [return_map]). +#{scheme => "http",path => "/a/g",host => "localhost-örebro"} + </pre> + </desc> + </func> + + <func> + <name name="parse" arity="1"/> + <fsummary>Parse URI into a map.</fsummary> + <desc> + <p>Parses an <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url> + compliant <c>uri_string()</c> into a <c>uri_map()</c>, that holds the parsed + components of the <c>URI</c>. + If parsing fails, an error tuple is returned.</p> + <p>See also the opposite operation <seealso marker="#recompose/1"> + <c>recompose/1</c></seealso>.</p> + <p><em>Example:</em></p> + <pre> +1> <input>uri_string:parse("foo://[email protected]:8042/over/there?name=ferret#nose").</input> +#{fragment => "nose",host => "example.com", + path => "/over/there",port => 8042,query => "name=ferret", + scheme => foo,userinfo => "user"} +2> <![CDATA[uri_string:parse(<<"foo://[email protected]:8042/over/there?name=ferret">>).]]> +<![CDATA[#{host => <<"example.com">>,path => <<"/over/there">>, + port => 8042,query => <<"name=ferret">>,scheme => <<"foo">>, + userinfo => <<"user">>}]]> + </pre> + </desc> + </func> + + <func> + <name name="recompose" arity="1"/> + <fsummary>Recompose URI.</fsummary> + <desc> + <p>Creates an <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url> compliant + <c><anno>URIString</anno></c> (percent-encoded), based on the components of + <c><anno>URIMap</anno></c>. + If the <c><anno>URIMap</anno></c> is invalid, an error tuple is returned.</p> + <p>See also the opposite operation <seealso marker="#parse/1"> + <c>parse/1</c></seealso>.</p> + <p><em>Example:</em></p> + <pre> +1> <input>URIMap = #{fragment => "nose", host => "example.com", path => "/over/there",</input> +1> port => 8042, query => "name=ferret", scheme => "foo", userinfo => "user"}. +#{fragment => "top",host => "example.com", + path => "/over/there",port => 8042,query => "?name=ferret", + scheme => foo,userinfo => "user"} + +2> <input>uri_string:recompose(URIMap).</input> +"foo://example.com:8042/over/there?name=ferret#nose"</pre> + </desc> + </func> + + <func> + <name name="transcode" arity="2"/> + <fsummary>Transcode URI.</fsummary> + <desc> + <p>Transcodes an <url href="https://www.ietf.org/rfc/rfc3986.txt">RFC 3986</url> + compliant <c><anno>URIString</anno></c>, + where <c><anno>Options</anno></c> is a list of tagged tuples, specifying the inbound + (<c>in_encoding</c>) and outbound (<c>out_encoding</c>) encodings. <c>in_encoding</c> + and <c>out_encoding</c> specifies both binary encoding and percent-encoding for the + input and output data. Mixed encoding, where binary encoding is not the same as + percent-encoding, is not supported. + If an argument is invalid, an error tuple is returned.</p> + <p><em>Example:</em></p> + <pre> +1> <input><![CDATA[uri_string:transcode(<<"foo%00%00%00%F6bar"/utf32>>,]]></input> +1> [{in_encoding, utf32},{out_encoding, utf8}]). +<![CDATA[<<"foo%C3%B6bar"/utf8>>]]> +2> uri_string:transcode("foo%F6bar", [{in_encoding, latin1}, +2> {out_encoding, utf8}]). +"foo%C3%B6bar" + </pre> + </desc> + </func> + + </funcs> +</erlref> |