diff options
Diffstat (limited to 'lib/stdlib/doc')
| -rw-r--r-- | lib/stdlib/doc/src/c.xml | 9 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/filelib.xml | 29 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/filename.xml | 30 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/gen_server.xml | 52 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/gen_statem.xml | 12 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/rand.xml | 118 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/string.xml | 396 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/unicode_usage.xml | 8 |
8 files changed, 248 insertions, 406 deletions
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/filelib.xml b/lib/stdlib/doc/src/filelib.xml index 80c4acffdb..5e631aac21 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 14fd5ef787..d2608ad542 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> @@ -555,6 +582,7 @@ unsafe</pre> ["a:/","msdev","include"]</pre> </desc> </func> + </funcs> </erlref> diff --git a/lib/stdlib/doc/src/gen_server.xml b/lib/stdlib/doc/src/gen_server.xml index 7d137fc772..da74e793e6 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> @@ -610,12 +619,15 @@ 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 +685,11 @@ 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 +704,41 @@ 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 +746,7 @@ 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 +776,7 @@ 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> diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index a7caa71dcb..4a824f073e 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -1329,7 +1329,7 @@ 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> @@ -1339,8 +1339,12 @@ 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> @@ -1851,7 +1855,7 @@ 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>, 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/string.xml b/lib/stdlib/doc/src/string.xml index 9d5edd9ecf..130fc74a28 100644 --- a/lib/stdlib/doc/src/string.xml +++ b/lib/stdlib/doc/src/string.xml @@ -109,10 +109,8 @@ <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. + clusters. The <c>old functions</c> that only work on Latin-1 lists as input + are kept for backwards compatibility reasons but should not be used. </p> </description> @@ -594,7 +592,7 @@ 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>. @@ -631,393 +629,5 @@ ÖÄÅ</pre> </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"/> - <name name="centre" arity="3"/> - <fsummary>Center a string.</fsummary> - <desc> - <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>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> - - <func> - <name name="chr" arity="2"/> - <fsummary>Return the index of the first occurrence of - a character in a string.</fsummary> - <desc> - <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> - - <func> - <name name="concat" arity="2"/> - <fsummary>Concatenate two strings.</fsummary> - <desc> - <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> - - <func> - <name name="copies" arity="2"/> - <fsummary>Copy a string.</fsummary> - <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> - - <func> - <name name="cspan" arity="2"/> - <fsummary>Span characters at start of a string.</fsummary> - <desc> - <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"). -0</code> - </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"], ", "). -"one, two, three"</code> - </desc> - </func> - - <func> - <name name="left" arity="2"/> - <name name="left" arity="3"/> - <fsummary>Adjust left end of a string.</fsummary> - <desc> - <p>Returns <c><anno>String</anno></c> with the length adjusted in - accordance with <c><anno>Number</anno></c>. The left margin is - 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,$.). -"Hello....."</code> - </desc> - </func> - - <func> - <name name="len" arity="1"/> - <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> - - <func> - <name name="rchr" arity="2"/> - <fsummary>Return the index of the last occurrence of - a character in a string.</fsummary> - <desc> - <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> - - <func> - <name name="right" arity="2"/> - <name name="right" arity="3"/> - <fsummary>Adjust right end of a string.</fsummary> - <desc> - <p>Returns <c><anno>String</anno></c> with the length adjusted in - accordance with <c><anno>Number</anno></c>. The right margin is - 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, $.). -".....Hello"</code> - </desc> - </func> - - <func> - <name name="rstr" arity="2"/> - <fsummary>Find the index of a substring.</fsummary> - <desc> - <p>Returns the position where the last occurrence of - <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"). -8</code> - </desc> - </func> - - <func> - <name name="span" arity="2"/> - <fsummary>Span characters at start of a string.</fsummary> - <desc> - <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"). -5</code> - </desc> - </func> - - <func> - <name name="str" arity="2"/> - <fsummary>Find the index of a substring.</fsummary> - <desc> - <p>Returns the position where the first occurrence of - <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"). -8</code> - </desc> - </func> - - <func> - <name name="strip" arity="1"/> - <name name="strip" arity="2"/> - <name name="strip" arity="3"/> - <fsummary>Strip leading or trailing characters.</fsummary> - <desc> - <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, $.). -"Hello"</code> - </desc> - </func> - - <func> - <name name="sub_string" arity="2"/> - <name name="sub_string" arity="3"/> - <fsummary>Extract a substring.</fsummary> - <desc> - <p>Returns a substring of <c><anno>String</anno></c>, starting at - position <c><anno>Start</anno></c> to the end of the string, or to - and including position <c><anno>Stop</anno></c>.</p> - <p>This function is <seealso marker="#oldapi">obsolete</seealso>. - Use - <seealso marker="#slice/3"><c>slice/3</c></seealso>.</p> - <p><em>Example:</em></p> - <code type="none"> -sub_string("Hello World", 4, 8). -"lo Wo"</code> - </desc> - </func> - - <func> - <name name="substr" arity="2"/> - <name name="substr" arity="3"/> - <fsummary>Return a substring of a string.</fsummary> - <desc> - <p>Returns a substring of <c><anno>String</anno></c>, starting at - position <c><anno>Start</anno></c>, and ending at the end of the - string or at length <c><anno>Length</anno></c>.</p> - <p>This function is <seealso marker="#oldapi">obsolete</seealso>. - Use - <seealso marker="#slice/3"><c>slice/3</c></seealso>.</p> - <p><em>Example:</em></p> - <code type="none"> -> substr("Hello World", 4, 5). -"lo Wo"</code> - </desc> - </func> - - <func> - <name name="sub_word" arity="2"/> - <name name="sub_word" arity="3"/> - <fsummary>Extract subword.</fsummary> - <desc> - <p>Returns the word in position <c><anno>Number</anno></c> of - <c><anno>String</anno></c>. Words are separated by blanks or - <c><anno>Character</anno></c>s.</p> - <p>This function is <seealso marker="#oldapi">obsolete</seealso>. - Use - <seealso marker="#nth_lexeme/3"><c>nth_lexeme/3</c></seealso>.</p> - <p><em>Example:</em></p> - <code type="none"> -> string:sub_word(" Hello old boy !",3,$o). -"ld b"</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"/> - <name name="to_upper" arity="1" clause_i="2"/> - <fsummary>Convert case of string (ISO/IEC 8859-1).</fsummary> - <type variable="String" name_i="1"/> - <type variable="Result" name_i="1"/> - <type variable="Char"/> - <type variable="CharResult"/> - <desc> - <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> - - <func> - <name name="tokens" arity="2"/> - <fsummary>Split string into tokens.</fsummary> - <desc> - <p>Returns a list of tokens in <c><anno>String</anno></c>, separated - by the characters in <c><anno>SeparatorList</anno></c>.</p> - <p><em>Example:</em></p> - <code type="none"> -> tokens("abc defxxghix jkl", "x "). -["abc", "def", "ghi", "jkl"]</code> - <p>Notice that, as shown in this example, two or more - 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> - - <func> - <name name="words" arity="1"/> - <name name="words" arity="2"/> - <fsummary>Count blank separated words.</fsummary> - <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). -4</code> - </desc> - </func> - </funcs> - - <section> - <title>Notes</title> - <p>Some of the general string functions can seem to overlap each - 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> - </section> - </erlref> 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 |