ruby-changes:27318
From: zzak <ko1@a...>
Date: Fri, 22 Feb 2013 11:12:27 +0900 (JST)
Subject: [ruby-changes:27318] zzak:r39370 (trunk): * enum.c (Enumerable#chunk: Improved examples, grammar, and formatting
zzak 2013-02-22 11:11:26 +0900 (Fri, 22 Feb 2013) New Revision: 39370 http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=rev&revision=39370 Log: * enum.c (Enumerable#chunk: Improved examples, grammar, and formatting Patch by Dan Bernier and Rich Bruchal of newhaven.rb [Github documenting-ruby/ruby#8] Modified files: trunk/ChangeLog trunk/enum.c Index: ChangeLog =================================================================== --- ChangeLog (revision 39369) +++ ChangeLog (revision 39370) @@ -1,3 +1,9 @@ https://github.com/ruby/ruby/blob/trunk/ChangeLog#L1 +Fri Feb 22 11:10:00 2013 Zachary Scott <zachary@z...> + + * enum.c (Enumerable#chunk: Improved examples, grammar, and formatting + Patch by Dan Bernier and Rich Bruchal of newhaven.rb + [Github documenting-ruby/ruby#8] + Fri Feb 22 11:00:00 2013 Zachary Scott <zachary@z...> * numeric.c: Examples and formatting for Numeric and Float Index: enum.c =================================================================== --- enum.c (revision 39369) +++ enum.c (revision 39370) @@ -2394,17 +2394,13 @@ chunk_i(VALUE yielder, VALUE enumerator, https://github.com/ruby/ruby/blob/trunk/enum.c#L2394 * enum.chunk { |elt| ... } -> an_enumerator * enum.chunk(initial_state) { |elt, state| ... } -> an_enumerator * - * Creates an enumerator for each chunked elements. - * The consecutive elements which have same block value are chunked. + * Enumerates over the items, chunking them together based on the return + * value of the block. * - * The result enumerator yields the block value and an array of chunked elements. - * So "each" method can be called as follows. - * - * enum.chunk { |elt| key }.each { |key, ary| ... } - * enum.chunk(initial_state) { |elt, state| key }.each { |key, ary| ... } + * Consecutive elements which return the same block value are chunked together. * * For example, consecutive even numbers and odd numbers can be - * splitted as follows. + * chunked as follows. * * [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5].chunk { |n| * n.even? @@ -2430,13 +2426,18 @@ chunk_i(VALUE yielder, VALUE enumerator, https://github.com/ruby/ruby/blob/trunk/enum.c#L2426 * # ["D", 791] * # ... * - * The following key values has special meaning: - * - nil and :_separator specifies that the elements are dropped. - * - :_alone specifies that the element should be chunked as a singleton. - * Other symbols which begins an underscore are reserved. + * The following key values have special meaning: + * - +nil+ and +:_separator+ specifies that the elements should be dropped. + * - +:_alone+ specifies that the element should be chunked by itself. + * + * Any other symbols that begin with an underscore will raise an error: + * + * items.chunk { |item| :_underscore } + * #=> RuntimeError: symbol begins with an underscore is reserved * - * nil and :_separator can be used to ignore some elements. - * For example, the sequence of hyphens in svn log can be eliminated as follows. + * +nil+ and +:_separator+ can be used to ignore some elements. + * + * For example, the sequence of hyphens in svn log can be eliminated as follows: * * sep = "-"*72 + "\n" * IO.popen("svn log README") { |f| @@ -2456,7 +2457,7 @@ chunk_i(VALUE yielder, VALUE enumerator, https://github.com/ruby/ruby/blob/trunk/enum.c#L2457 * # "\n"] * # ... * - * paragraphs separated by empty lines can be parsed as follows. + * Paragraphs separated by empty lines can be parsed as follows: * * File.foreach("README").chunk { |line| * /\A\s*\z/ !~ line || nil @@ -2464,26 +2465,22 @@ chunk_i(VALUE yielder, VALUE enumerator, https://github.com/ruby/ruby/blob/trunk/enum.c#L2465 * pp lines * } * - * :_alone can be used to pass through bunch of elements. - * For example, sort consecutive lines formed as Foo#bar and - * pass other lines, chunk can be used as follows. + * +:_alone+ can be used to force items into their own chunk. + * For example, you can put lines that contain a URL by themselves, + * and chunk the rest of the lines together, like this: * - * pat = /\A[A-Z][A-Za-z0-9_]+\#/ + * pattern = /http/ * open(filename) { |f| - * f.chunk { |line| pat =~ line ? $& : :_alone }.each { |key, lines| - * if key != :_alone - * print lines.sort.join('') - * else - * print lines.join('') - * end + * f.chunk { |line| line =~ pattern ? :_alone : true }.each { |key, lines| + * pp lines * } * } * * If the block needs to maintain state over multiple elements, - * _initial_state_ argument can be used. - * If non-nil value is given, - * it is duplicated for each "each" method invocation of the enumerator. - * The duplicated object is passed to 2nd argument of the block for "chunk" method. + * an +initial_state+ argument can be used. + * If a non-nil value is given, + * a reference to it is passed as the 2nd argument of the block for the + * +chunk+ method, so state-changes to it persist across block calls. * */ static VALUE -- ML: ruby-changes@q... Info: http://www.atdot.net/~ko1/quickml/