diff --git a/ChangeLog b/ChangeLog index 5d5653f2cd..775f4e0c51 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +Tue Oct 16 01:31:23 2007 Yukihiro Matsumoto + + * enum.c (enum_inject): RDoc update. a patch from David Flanagan + in [ruby-core:12679] + Tue Oct 16 01:25:40 2007 Yukihiro Matsumoto * encoding.c (Init_Encoding): define #to_s to show encoding name diff --git a/enum.c b/enum.c index fa4b480f9f..d9e054e8fd 100644 --- a/enum.c +++ b/enum.c @@ -362,67 +362,50 @@ inject_op_i(VALUE i, VALUE p) } /* - * Document-method: inject * call-seq: - * enum.inject(sym) => obj * enum.inject(sym, initial) => obj + * enum.inject(sym) => obj * enum.inject(initial) {| memo, obj | block } => obj * enum.inject {| memo, obj | block } => obj + * + * enum.reduce(sym, initial) => obj + * enum.reduce(sym) => obj + * enum.reduce(initial) {| memo, obj | block } => obj + * enum.reduce {| memo, obj | block } => obj * - * Combines the elements of enum by applying the block to an - * accumulator value (memo) and each element in turn. At each - * step, memo is set to the value returned by the block. The - * first form lets you supply an initial value for memo. The - * second form uses the first element of the collection as a the - * initial value (and skips that element while iterating). - * See also Enumerable#reduce. - * + * Combines all elements of enum by applying a binary + * operation, specified by a block or a symbol that names a + * method or operator. + * + * If you specify a block, then for each element in enum + * the block is passed an accumulator value (memo) and the element. + * If you specify a symbol instead, then each element in the collection + * will be passed to the named method of memo. + * In either case, the result becomes the new value for memo. + * At the end of the iteration, the final value of memo is the + * return value fo the method. + * + * If you do not explicitly specify an initial value for memo, + * then uses the first element of collection is used as the initial value + * of memo. + * + * Examples: + * * # Sum some numbers - * (5..10).inject {|sum, n| sum + n } #=> 45 + * (5..10).reduce(:+) #=> 45 + * # Same using a block and inject + * (5..10).inject {|sum, n| sum + n } #=> 45 * # Multiply some numbers - * (5..10).inject(1) {|product, n| product * n } #=> 151200 - * + * (5..10).reduce(:*, 1) #=> 151200 + * # Same using a block + * (5..10).inject(1) {|product, n| product * n } #=> 151200 * # find the longest word * longest = %w{ cat sheep bear }.inject do |memo,word| * memo.length > word.length ? memo : word * end - * longest #=> "sheep" - * - * # find the length of the longest word - * longest = %w{ cat sheep bear }.inject(0) do |memo,word| - * memo >= word.length ? memo : word.length - * end - * longest #=> 5 + * longest #=> "sheep" * */ - -/* - * Document-method: reduce - * call-seq: - * enum.reduce(sym) => obj - * enum.reduce(sym, initial) => obj - * enum.reduce {| memo, obj | block } => obj - * enum.reduce(initial) {| memo, obj | block } => obj - * - * Combines all elements of enum by applying a binary - * operation, specified by the block or metho-name symbol, for - * example, ary.reduce(:+) adds up all the elements. If no block is - * specified, the first argument is a method (or operator) name that - * takes two arguments. The second optional argument is the initial - * value. If a block is specified, the first optional value is the - * initial value. - * - * # Sum some numbers - * (5..10).reduce(:+) #=> 45 - * # Same using a block - * (5..10).reduce {|sum, n| sum + n } #=> 45 - * # Multiply some numbers - * (5..10).reduce(:*, 1) #=> 151200 - * # Same using a block - * (5..10).reduce(1) {|product, n| product * n } #=> 151200 - * - */ - static VALUE enum_inject(int argc, VALUE *argv, VALUE obj) { @@ -855,7 +838,7 @@ one_iter_i(VALUE i, VALUE *memo) * Passes each element of the collection to the given block. The method * returns true if the block returns true * exactly once. If the block is not given, one? will return - * true only if exactly one of the collection members are + * true only if exactly one of the collection members is * true. * * %w{ant bear cat}.one? {|word| word.length == 4} #=> true @@ -897,15 +880,15 @@ none_iter_i(VALUE i, VALUE *memo) * * Passes each element of the collection to the given block. The method * returns true if the block never returns true - * for all elements. If the block is not given, one? will return - * true only if any of the collection members is true. - * - * %w{ant bear cat}.one? {|word| word.length == 4} #=> true - * %w{ant bear cat}.one? {|word| word.length >= 4} #=> false - * [ nil, true, 99 ].one? #=> true + * for all elements. If the block is not given, none? will return + * true only if none of the collection members is true. * + * %w{ant bear cat}.none? {|word| word.length == 5} #=> true + * %w{ant bear cat}.none? {|word| word.length >= 4} #=> false + * [].none? #=> true + * [nil].none? #=> true + * [nil,false].none? #=> true */ - static VALUE enum_none(VALUE obj) {