diff options
| author | Erlang/OTP <[email protected]> | 2010-05-20 10:01:54 +0000 |
|---|---|---|
| committer | Erlang/OTP <[email protected]> | 2010-05-20 10:01:54 +0000 |
| commit | c0895d14994c5e98b1171b0174c70a0244d52f86 (patch) | |
| tree | 9cd67f70ed7898bed9460f73d493ac6064213bd8 /lib/stdlib/doc/src | |
| parent | db16e96833094bf3b13d562388b3de02bba8d73d (diff) | |
| parent | 97ab480df55cf574ab42a87b6927ef5bba83000e (diff) | |
| download | otp-c0895d14994c5e98b1171b0174c70a0244d52f86.tar.gz otp-c0895d14994c5e98b1171b0174c70a0244d52f86.tar.bz2 otp-c0895d14994c5e98b1171b0174c70a0244d52f86.zip | |
Merge branch 'pan/otp_8217_binary' into dev
* pan/otp_8217_binary:
Add documentation for binary module
Add more tests and make some go easier on small systems
Correct Boyer More and trapping for longest_common_suffix
Add longer timetrap to testcases and add binary to app file
Add guard BIFs binary_part/2,3
Add binary:{encode,decode}_unsigned({1,2}
Add referenced_byte_size/1
Add binary:list_to_bin/1 and binary:copy/1,2
Add bin_to_list/{1,2,3}
Add binary:longest_common_prefix/longest_common_suffix
Add binary:part to erl_bif_binary.c
Move binary module bif's to erl_bif_binary.c
Count reductions for process even when not trapping
Add random compare testcase
Teach BIF's binary:match/matches interrupting/restarting
Teach binary.c the semantics to take longest instead of shortest match
Initial commit of the binary EEP
OTP-8217 Implement EEP31
The module binary from EEP31 (and EEP9) is implemented.
Diffstat (limited to 'lib/stdlib/doc/src')
| -rw-r--r-- | lib/stdlib/doc/src/Makefile | 11 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/binary.xml | 729 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/ref_man.xml | 7 |
3 files changed, 739 insertions, 8 deletions
diff --git a/lib/stdlib/doc/src/Makefile b/lib/stdlib/doc/src/Makefile index 13b9b2ff18..b558697d63 100644 --- a/lib/stdlib/doc/src/Makefile +++ b/lib/stdlib/doc/src/Makefile @@ -1,19 +1,19 @@ # # %CopyrightBegin% -# -# Copyright Ericsson AB 1997-2009. All Rights Reserved. -# +# +# Copyright Ericsson AB 1997-2010. All Rights Reserved. +# # The contents of this file are subject to the Erlang Public License, # Version 1.1, (the "License"); you may not use this file except in # compliance with the License. You should have received a copy of the # Erlang Public License along with this software. If not, it can be # retrieved online at http://www.erlang.org/. -# +# # Software distributed under the License is distributed on an "AS IS" # basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See # the License for the specific language governing rights and limitations # under the License. -# +# # %CopyrightEnd% # include $(ERL_TOP)/make/target.mk @@ -40,6 +40,7 @@ XML_REF3_FILES = \ array.xml \ base64.xml \ beam_lib.xml \ + binary.xml \ c.xml \ calendar.xml \ dets.xml \ diff --git a/lib/stdlib/doc/src/binary.xml b/lib/stdlib/doc/src/binary.xml new file mode 100644 index 0000000000..05ec4406c6 --- /dev/null +++ b/lib/stdlib/doc/src/binary.xml @@ -0,0 +1,729 @@ +<?xml version="1.0" encoding="latin1" ?> +<!DOCTYPE erlref SYSTEM "erlref.dtd"> + +<erlref> + <header> + <copyright> + <year>2009</year> + <year>2010</year> + <holder>Ericsson AB, All Rights Reserved</holder> + </copyright> + <legalnotice> + The contents of this file are subject to the Erlang Public License, + Version 1.1, (the "License"); you may not use this file except in + compliance with the License. You should have received a copy of the + Erlang Public License along with this software. If not, it can be + retrieved on line at http://www.erlang.org/. + + Software distributed under the License is distributed on an "AS IS" + basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + the License for the specific language governing rights and limitations + under the License. + + The Initial Developer of the Original Code is Ericsson AB. + </legalnotice> + + <title>binary</title> + <prepared>Patrik Nyblom</prepared> + <responsible>Kenneth Lundin</responsible> + <docno>1</docno> + <approved></approved> + <checked></checked> + <date>2010-05-05</date> + <rev>A</rev> + <file>binary.xml</file> + </header> + <module>binary</module> + <modulesummary>Library for handling binary data</modulesummary> + <description> + + <p>This module contains functions for manipulating byte-oriented + binaries. Although the majority of functions could be implemented + using bit-syntax, the functions in this library are highly + optimized and are expected to either execute faster or consume + less memory (or both) than a counterpart written in pure Erlang.</p> + + <p>The module is implemented according to the EEP (Erlang Enhancement Proposal) 31.</p> + + <note> + <p> + The library handles byte-oriented data. Bitstrings that are not + binaries (does not contain whole octets of bits) will result in a <c>badarg</c> + exception being thrown from any of the functions in this + module. + </p> + </note> + + + </description> + <section> + <title>DATA TYPES</title> + <code type="none"> + cp() + - Opaque data-type representing a compiled search-pattern. Guaranteed to be a tuple() + to allow programs to distinguish it from non precompiled search patterns. + </code> + <code type="none"> + part() = {Start,Length} + Start = int() + Length = int() + - A representaion of a part (or range) in a binary. Start is a + zero-based offset into a binary() and Length is the length of + that part. As input to functions in this module, a reverse + part specification is allowed, constructed with a negative + Length, so that the part of the binary begins at Start + + Length and is -Length long. This is useful for referencing the + last N bytes of a binary as {size(Binary), -N}. The functions + in this module always return part()'s with positive Length. + </code> + </section> + <funcs> + <func> + <name>at(Subject, Pos) -> int()</name> + <fsummary>Returns the byte at a specific position in a binary</fsummary> + <type> + <v>Subject = binary()</v> + <v>Pos = int() >= 0</v> + </type> + <desc> + + <p>Returns the byte at position <c>Pos</c> (zero-based) in the binary + <c>Subject</c> as an integer. If <c>Pos</c> >= <c>byte_size(Subject)</c>, + a <c>badarg</c> + exception is raised.</p> + + </desc> + </func> + <func> + <name>bin_to_list(Subject) -> list()</name> + <fsummary>Convert a binary to a list of integers</fsummary> + <type> + <v>Subject = binary()</v> + </type> + <desc> + <p>The same as <c>bin_to_list(Subject,{0,byte_size(Subject)})</c>.</p> + </desc> + </func> + <func> + <name>bin_to_list(Subject, PosLen) -> list()</name> + <fsummary>Convert a binary to a list of integers</fsummary> + <type> + <v>Subject = binary()</v> + <v>PosLen = part()</v> + </type> + <desc> + + <p>Converts <c>Subject</c> to a list of <c>int()</c>s, each representing + the value of one byte. The <c>part()</c> denotes which part of the + <c>binary()</c> to convert. Example:</p> + +<code> +1> binary:bin_to_list(<<"erlang">>,{1,3}). +"rla" +%% or [114,108,97] in list notation. +</code> + <p>If <c>PosLen</c> in any way references outside the binary, a <c>badarg</c> exception is raised.</p> + </desc> + </func> + <func> + <name>bin_to_list(Subject, Pos, Len) -> list()</name> + <fsummary>Convert a binary to a list of integers</fsummary> + <type> + <v>Subject = binary()</v> + <v>Pos = int()</v> + <v>Len = int()</v> + </type> + <desc> + <p>The same as<c> bin_to_list(Subject,{Pos,Len})</c>.</p> + </desc> + </func> + <func> + <name>compile_pattern(Pattern) -> cp()</name> + <fsummary>Pre-compiles a binary search pattern</fsummary> + <type> + <v>Pattern = binary() | [ binary() ]</v> + </type> + <desc> + + <p>Builds an internal structure representing a compilation of a + search-pattern, later to be used in the <seealso marker="#match-3">match/3</seealso>, + <seealso marker="#matches-3">matches/3</seealso>, + <seealso marker="#split-3">split/3</seealso> or + <seealso marker="#replace-4">replace/4</seealso> + functions. The <c>cp()</c> returned is guaranteed to be a + <c>tuple()</c> to allow programs to distinguish it from non + pre-compiled search patterns</p> + + <p>When a list of binaries is given, it denotes a set of + alternative binaries to search for. I.e if + <c>[<<"functional">>,<<"programming">>]</c> + is given as <c>Pattern</c>, this + means "either <c><<"functional">></c> or + <c><<"programming">></c>". The pattern is a set of + alternatives; when only a single binary is given, the set has + only one element. The order of alternatives in a pattern is not significant.</p> + + <p>The list of binaries used for search alternatives shall be flat and proper.</p> + + <p>If <c>Pattern</c> is not a binary or a flat proper list of binaries with length > 0, + a <c>badarg</c> exception will be raised.</p> + + </desc> + </func> + <func> + <name>copy(Subject) -> binary()</name> + <fsummary>Creates a duplicate of a binary</fsummary> + <type> + <v>Subject = binary()</v> + </type> + <desc> + <p>The same as <c>copy(Subject, 1)</c>.</p> + </desc> + </func> + <func> + <name>copy(Subject,N) -> binary()</name> + <fsummary>Duplicates a binary N times and creates a new</fsummary> + <type> + <v>Subject = binary()</v> + <v>N = int() >= 0</v> + </type> + <desc> + <p>Creates a binary with the content of <c>Subject</c> duplicated <c>N</c> times.</p> + + <p>This function will always create a new binary, even if <c>N = + 1</c>. By using <c>copy/1</c> on a binary referencing a larger binary, one + might free up the larger binary for garbage collection.</p> + + <note> + <p>By deliberately copying a single binary to avoid referencing + a larger binary, one might, instead of freeing up the larger + binary for later garbage collection, create much more binary + data than needed. Sharing binary data is usually good. Only in + special cases, when small parts reference large binaries and the + large binaries are no longer used in any process, deliberate + copying might be a good idea.</p> </note> + + <p>If <c>N</c> < <c>0</c>, a <c>badarg</c> exception is raised.</p> + </desc> + </func> + <func> + <name>decode_unsigned(Subject) -> Unsigned</name> + <fsummary>Decode a whole binary into an integer of arbitrary size</fsummary> + <type> + <v>Subject = binary()</v> + <v>Unsigned = int() >= 0</v> + </type> + <desc> + <p>The same as <c>decode_unsigned(Subject,big)</c>.</p> + </desc> + </func> + <func> + <name>decode_unsigned(Subject, Endianess) -> Unsigned</name> + <fsummary>Decode a whole binary into an integer of arbitrary size</fsummary> + <type> + <v>Subject = binary()</v> + <v>Endianess = big | little</v> + <v>Unsigned = int() >= 0</v> + </type> + <desc> + + <p>Converts the binary digit representation, in big or little + endian, of a positive integer in <c>Subject</c> to an Erlang <c>int()</c>.</p> + + <p>Example:</p> + + <code> +1> binary:decode_unsigned(<<169,138,199>>,big). +11111111 + </code> + </desc> + </func> + <func> + <name>encode_unsigned(Unsigned) -> binary()</name> + <fsummary>Encodes an unsigned integer into the minimal binary</fsummary> + <type> + <v>Unsigned = int() >= 0</v> + </type> + <desc> + <p>The same as <c>encode_unsigned(Unsigned,big)</c>.</p> + </desc> + </func> + <func> + <name>encode_unsigned(Unsigned,Endianess) -> binary()</name> + <fsummary>Encodes an unsigned integer into the minimal binary</fsummary> + <type> + <v>Unsigned = int() >= 0</v> + <v>Endianess = big | little</v> + </type> + <desc> + + <p>Converts a positive integer to the smallest possible + representation in a binary digit representation, either big + or little endian.</p> + + <p>Example:</p> + + <code> +1> binary:encode_unsigned(11111111,big). +<<169,138,199>> + </code> + </desc> + </func> + <func> + <name>first(Subject) -> int()</name> + <fsummary>Returns the first byte of a binary</fsummary> + <type> + <v>Subject = binary()</v> + </type> + <desc> + + <p>Returns the first byte of the binary <c>Subject</c> as an integer. If the + size of <c>Subject</c> is zero, a <c>badarg</c> exception is raised.</p> + + </desc> + </func> + <func> + <name>last(Subject) -> int()</name> + <fsummary>Returns the last byte of a binary</fsummary> + <type> + <v>Subject = binary()</v> + </type> + <desc> + + <p>Returns the last byte of the binary <c>Subject</c> as an integer. If the + size of <c>Subject</c> is zero, a <c>badarg</c> exception is raised.</p> + + </desc> + </func> + <func> + <name>list_to_bin(ByteList) -> binary()</name> + <fsummary>Convert a list of integers and binaries to a binary</fsummary> + <type> + <v>ByteList = iodata() (see module erlang)</v> + </type> + <desc> + <p>Works exactly as <c>erlang:list_to_binary/1</c>, added for completeness.</p> + </desc> + </func> + <func> + <name>longest_common_prefix(Binaries) -> int()</name> + <fsummary>Returns length of longest common prefix for a set of binaries</fsummary> + <type> + <v>Binaries = [ binary() ]</v> + </type> + <desc> + + <p>Returns the length of the longest common prefix of the + binaries in the list <c>Binaries</c>. Example:</p> + +<code> +1> binary:longest_common_prefix([<<"erlang">>,<<"ergonomy">>]). +2 +2> binary:longest_common_prefix([<<"erlang">>,<<"perl">>]). +0 +</code> + + <p>If <c>Binaries</c> is not a flat list of binaries, a <c>badarg</c> exception is raised.</p> + </desc> + </func> + <func> + <name>longest_common_suffix(Binaries) -> int()</name> + <fsummary>Returns length of longest common suffix for a set of binaries</fsummary> + <type> + <v>Binaries = [ binary() ]</v> + </type> + <desc> + + <p>Returns the length of the longest common suffix of the + binaries in the list <c>Binaries</c>. Example:</p> + +<code> +1> binary:longest_common_suffix([<<"erlang">>,<<"fang">>]). +3 +2> binary:longest_common_suffix([<<"erlang">>,<<"perl">>]). +0 +</code> + + <p>If <c>Binaries</c> is not a flat list of binaries, a <c>badarg</c> exception is raised.</p> + + </desc> + </func> + <func> + <name>match(Subject, Pattern) -> Found | <c>nomatch</c></name> + <fsummary>Searches for the first match of a pattern in a binary</fsummary> + <type> + <v>Subject = binary()</v> + <v>Pattern = binary() | [ binary() ] | cp()</v> + <v>Found = part()</v> + </type> + <desc> + <p>The same as <c>match(Subject, Pattern, [])</c>.</p> + </desc> + </func> + <func> + <name>match(Subject,Pattern,Options) -> Found | <c>nomatch</c></name> + <fsummary>Searches for the first match of a pattern in a binary</fsummary> + <type> + <v>Subject = binary()</v> + <v>Pattern = binary() | [ binary() ] | cp()</v> + <v>Found = part()</v> + <v>Options = [ Option ]</v> + <v>Option = {scope, part()}</v> + </type> + <desc> + + <p>Searches for the first occurrence of <c>Pattern</c> in <c>Subject</c> and + returns the position and length.</p> + + <p>The function will return <c>{Pos,Length}</c> for the binary + in <c>Pattern</c> starting at the lowest position in + <c>Subject</c>, Example:</p> + +<code> +1> binary:match(<<"abcde">>, [<<"bcde">>,<<"cd">>],[]). +{1,4} +</code> + + <p>Even though <c><<"cd">></c> ends before + <c><<"bcde">></c>, <c><<"bcde">></c> + begins first and is therefore the first match. If two + overlapping matches begins at the same position, the longest is + returned.</p> + + <p>Summary of the options:</p> + + <taglist> + <tag>{scope, {Start, Length}}</tag> + <item><p>Only the given part is searched. Return values still have + offsets from the beginning of <c>Subject</c>. A negative <c>Length</c> is + allowed as described in the <c>TYPES</c> section of this manual.</p></item> + </taglist> + + <p>If none of the strings in + <c>Pattern</c> is found, the atom <c>nomatch</c> is returned.</p> + + <p>For a description of <c>Pattern</c>, see + <seealso marker="#compile_pattern-1">compile_pattern/1</seealso>.</p> + + <p>If <c>{scope, {Start,Length}}</c> is given in the options + such that <c>Start</c> is larger than the size of + <c>Subject</c>, <c>Start + Length</c> is less than zero or + <c>Start + Length</c> is larger than the size of + <c>Subject</c>, a <c>badarg</c> exception is raised.</p> + + </desc> + </func> + <func> + <name>matches(Subject, Pattern) -> Found</name> + <fsummary>Searches for all matches of a pattern in a binary</fsummary> + <type> + <v>Subject = binary()</v> + <v>Pattern = binary() | [ binary() ] | cp()</v> + <v>Found = [ part() ] | []</v> + </type> + <desc> + <p>The same as <c>matches(Subject, Pattern, [])</c>.</p> + </desc> + </func> + <func> + <name>matches(Subject,Pattern,Options) -> Found</name> + <fsummary>Searches for all matches of a pattern in a binary</fsummary> + <type> + <v>Subject = binary()</v> + <v>Pattern = binary() | [ binary() ] | cp()</v> + <v>Found = [ part() ] | []</v> + <v>Options = [ Option ]</v> + <v>Option = {scope, part()}</v> + </type> + <desc> + + <p>Works like match, but the <c>Subject</c> is searched until + exhausted and a list of all non-overlapping parts matching + <c>Pattern</c> is returned (in order). </p> + + <p>The first and longest match is preferred to a shorter, + which is illustrated by the following example:</p> + +<code> +1> binary:matches(<<"abcde">>, + [<<"bcde">>,<<"bc">>>,<<"de">>],[]). +[{1,4}] +</code> + + <p>The result shows that <<bcde">> is selected instead of the + shorter match <<"bc">> (which would have given raise to one + more match,<<"de">>). This corresponds to the behavior of posix + regular expressions (and programs like awk), but is not + consistent with alternative matches in re (and Perl), where + instead lexical ordering in the search pattern selects which + string matches.</p> + + <p>If none of the strings in pattern is found, an empty list is returned.</p> + + <p>For a description of <c>Pattern</c>, see <seealso marker="#compile_pattern-1">compile_pattern/1</seealso> and for a + description of available options, see <seealso marker="#match-3">match/3</seealso>.</p> + + <p>If <c>{scope, {Start,Length}}</c> is given in the options such that + <c>Start</c> is larger than the size of <c>Subject</c>, <c>Start + Length</c> is + less than zero or <c>Start + Length</c> is larger than the size of + <c>Subject</c>, a <c>badarg</c> exception is raised.</p> + + </desc> + </func> + <func> + <name>part(Subject, PosLen) -> binary()</name> + <fsummary>Extracts a part of a binary</fsummary> + <type> + <v>Subject = binary()</v> + <v>PosLen = part()</v> + </type> + <desc> + + <p>Extracts the part of the binary <c>Subject</c> described by <c>PosLen</c>.</p> + + <p>Negative length can be used to extract bytes at the end of a binary:</p> + +<code> +1> Bin = <<1,2,3,4,5,6,7,8,9,10>>. +2> binary:part(Bin,{byte_size(Bin), -5)). +<<6,7,8,9,10>> +</code> + + <note> + <p><seealso marker="#part-2">part/2</seealso>and <seealso + marker="#part-3">part/3</seealso> are also available in the + <c>erlang</c> module under the names <c>binary_part/2</c> and + <c>binary_part/3</c>. Those BIFs are allowed in guard tests.</p> + </note> + + <p>If <c>PosLen</c> in any way references outside the binary, a <c>badarg</c> exception + is raised.</p> + + </desc> + </func> + <func> + <name>part(Subject, Pos, Len) -> binary()</name> + <fsummary>Extracts a part of a binary</fsummary> + <type> + <v>Subject = binary()</v> + <v>Pos = int()</v> + <v>Len = int()</v> + </type> + <desc> + <p>The same as <c>part(Subject, {Pos, Len})</c>.</p> + </desc> + </func> + <func> + <name>referenced_byte_size(binary()) -> int()</name> + <fsummary>Determines the size of the actual binary pointed out by a sub-binary</fsummary> + <desc> + + <p>If a binary references a larger binary (often described as + being a sub-binary), it can be useful to get the size of the + actual referenced binary. This function can be used in a program + to trigger the use of <c>copy/1</c>. By copying a binary, one might + dereference the original, possibly large, binary which a smaller + binary is a reference to.</p> + + <p>Example:</p> + + <code> +store(Binary, GBSet) -> + NewBin = + case binary:referenced_byte_size(Binary) of + Large when Large > 2 * byte_size(Binary) -> + binary:copy(Binary); + _ -> + Binary + end, + gb_sets:insert(NewBin,GBSet). + </code> + + <p>In this example, we chose to copy the binary content before + inserting it in the <c>gb_set()</c> if it references a binary more than + twice the size of the data we're going to keep. Of course + different rules for when copying will apply to different + programs.</p> + + <p>Binary sharing will occur whenever binaries are taken apart, + this is the fundamental reason why binaries are fast, + decomposition can always be done with O(1) complexity. In rare + circumstances this data sharing is however undesirable, why this + function together with <c>copy/1</c> might be useful when optimizing + for memory use.</p> + + <p>Example of binary sharing:</p> + + <code> +1> A = binary:copy(<<1>>,100). +<<1,1,1,1,1 ... +2> byte_size(A). +100 +3> binary:referenced_byte_size(A) +100 +4> <<_:10/binary,B:10/binary,_/binary>> = A. +<<1,1,1,1,1 ... +5> byte_size(B). +10 +6> binary:referenced_byte_size(B) +100 + </code> + + <note> + <p>Binary data is shared among processes. If another process + still references the larger binary, copying the part this + process uses only consumes more memory and will not free up the + larger binary for garbage collection. Use this kind of intrusive + functions with extreme care, and only if a real problem is + detected.</p> + </note> + + </desc> + </func> + <func> + <name>replace(Subject,Pattern,Replacement) -> Result</name> + <fsummary>Replaces bytes in a binary according to a pattern</fsummary> + <type> + <v>Subject = binary()</v> + <v>Pattern = binary() | [ binary() ] | cp()</v> + <v>Replacement = binary()</v> + <v>Result = binary()</v> + </type> + <desc> + <p>The same as <c>replace(Subject,Pattern,Replacement,[])</c>.</p> + </desc> + </func> + <func> + <name>replace(Subject,Pattern,Replacement,Options) -> Result</name> + <fsummary>Replaces bytes in a binary according to a pattern</fsummary> + <type> + <v>Subject = binary()</v> + <v>Pattern = binary() | [ binary() ] | cp()</v> + <v>Replacement = binary()</v> + <v>Result = binary()</v> + <v>Options = [ Option ]</v> + <v>Option = global | {scope, part()} | {insert_replaced, InsPos}</v> + <v>InsPos = OnePos | [ OnePos ]</v> + <v>OnePos = int() =< byte_size(Replacement)</v> + </type> + <desc> + + <p>Constructs a new binary by replacing the parts in + <c>Subject</c> matching <c>Pattern</c> with the content of + <c>Replacement</c>.</p> + + <p>If the matching sub-part of <c>Subject</c> giving raise to the + replacement is to be inserted in the result, the option + <c>{insert_replaced, InsPos}</c> will insert the matching part into + <c>Replacement</c> at the given position (or positions) before actually + inserting <c>Replacement</c> into the <c>Subject</c>. Example:</p> + +<code> +1> binary:replace(<<"abcde">>,<<"b">>,<<"[]">>,[{insert_replaced,1}]). +<<"a[b]cde">> +2> binary:replace(<<"abcde">>,[<<"b">>,<<"d">>],<<"[]">>, + [global,{insert_replaced,1}]). +<<"a[b]c[d]e">> +3> binary:replace(<<"abcde">>,[<<"b">>,<<"d">>],<<"[]">>, + [global,{insert_replaced,[1,1]}]). +<<"a[bb]c[dd]e">> +4> binary:replace(<<"abcde">>,[<<"b">>,<<"d">>],<<"[-]">>, + [global,{insert_replaced,[1,2]}]). +<<"a[b-b]c[d-d]e">> +</code> + + <p>If any position given in <c>InsPos</c> is greater than the size of the replacement binary, a <c>badarg</c> exception is raised.</p> + + <p>The options <c>global</c> and <c>{scope, part()}</c> works as for <seealso marker="#split-3">split/3</seealso>. The return type is always a <c>binary()</c>.</p> + + <p>For a description of <c>Pattern</c>, see <seealso marker="#compile_pattern-1">compile_pattern/1</seealso>.</p> + </desc> + </func> + <func> + <name>split(Subject,Pattern) -> Parts</name> + <fsummary>Splits a binary according to a pattern</fsummary> + <type> + <v>Subject = binary()</v> + <v>Pattern = binary() | [ binary() ] | cp()</v> + <v>Parts = [ binary() ]</v> + </type> + <desc> + <p>The same as <c>split(Subject, Pattern, [])</c>.</p> + </desc> + </func> + <func> + <name>split(Subject,Pattern,Options) -> Parts</name> + <fsummary>Splits a binary according to a pattern</fsummary> + <type> + <v>Subject = binary()</v> + <v>Pattern = binary() | [ binary() ] | cp()</v> + <v>Parts = [ binary() ]</v> + <v>Options = [ Option ]</v> + <v>Option = {scope, part()} | trim | global</v> + </type> + <desc> + + <p>Splits Binary into a list of binaries based on Pattern. If + the option global is not given, only the first occurrence of + Pattern in Subject will give rise to a split.</p> + + <p>The parts of Pattern actually found in Subject are not included in the result.</p> + + <p>Example:</p> + +<code> +1> binary:split(<<1,255,4,0,0,0,2,3>>, [<<0,0,0>>,<<2>>],[]). +[<<1,255,4>>, <<2,3>>] +2> binary:split(<<0,1,0,0,4,255,255,9>>, [<<0,0>>, <<255,255>>],[global]). +[<<0,1>>,<<4>>,<<9>>] +</code> + + <p>Summary of options:</p> + <taglist> + + <tag>{scope, part()}</tag> + + <item><p>Works as in <seealso marker="#match-3">match/3</seealso> and + <seealso marker="#matches-3">matches/3</seealso>. Note that + this only defines the scope of the search for matching strings, + it does not cut the binary before splitting. The bytes before + and after the scope will be kept in the result. See example + below.</p></item> + + <tag>trim</tag> + + <item><p>Removes trailing empty parts of the result (as does trim in <c>re:split/3</c>)</p></item> + + <tag>global</tag> + + <item><p>Repeats the split until the <c>Subject</c> is + exhausted. Conceptually the global option makes split work on + the positions returned by <seealso marker="#matches-3">matches/3</seealso>, + while it normally + works on the position returned by + <seealso marker="#match-3">match/3</seealso>.</p></item> + + </taglist> + + <p>Example of the difference between a scope and taking the + binary apart before splitting:</p> + +<code> +1> binary:split(<<"banana">>,[<<"a">>],[{scope,{2,3}}]). +[<<"ban">>,<<"na">>] +2> binary:split(binary:part(<<"banana">>,{2,3}),[<<"a">>],[]). +[<<"n">>,<<"n">>] +</code> + + <p>The return type is always a list of binaries that are all + referencing <c>Subject</c>. This means that the data in <c>Subject</c> is not + actually copied to new binaries and that <c>Subject</c> cannot be + garbage collected until the results of the split are no longer + referenced.</p> + + <p>For a description of <c>Pattern</c>, see <seealso marker="#compile_pattern-1">compile_pattern/1</seealso>.</p> + + </desc> + </func> + </funcs> +</erlref> diff --git a/lib/stdlib/doc/src/ref_man.xml b/lib/stdlib/doc/src/ref_man.xml index f6ae368e92..85aae6151d 100644 --- a/lib/stdlib/doc/src/ref_man.xml +++ b/lib/stdlib/doc/src/ref_man.xml @@ -4,7 +4,7 @@ <application xmlns:xi="http://www.w3.org/2001/XInclude"> <header> <copyright> - <year>1996</year><year>2009</year> + <year>1996</year><year>2010</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -13,12 +13,12 @@ compliance with the License. You should have received a copy of the Erlang Public License along with this software. If not, it can be retrieved online at http://www.erlang.org/. - + Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the specific language governing rights and limitations under the License. - + </legalnotice> <title>STDLIB Reference Manual</title> @@ -37,6 +37,7 @@ <xi:include href="array.xml"/> <xi:include href="base64.xml"/> <xi:include href="beam_lib.xml"/> + <xi:include href="binary.xml"/> <xi:include href="c.xml"/> <xi:include href="calendar.xml"/> <xi:include href="dets.xml"/> |