From 84f0b051de55b80211eab0ad2438f500af45e4a5 Mon Sep 17 00:00:00 2001 From: dave Date: Thu, 18 Dec 2003 21:08:25 +0000 Subject: Annotate enum.c. Add pager support, and report on methods in included modules git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@5214 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- enum.c | 334 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 334 insertions(+) (limited to 'enum.c') diff --git a/enum.c b/enum.c index ee0b05838f..28f28cbd5f 100644 --- a/enum.c +++ b/enum.c @@ -44,6 +44,24 @@ grep_iter_i(i, arg) return Qnil; } +/* + * call-seq: + * enum.grep(pattern) => array + * enum.grep(pattern) {| obj | block } => array + * + * Returns an array of every element in enum for which + * Pattern === element. If the optional block is + * supplied, each matching element is passed to it, and the block's + * result is stored in the output array. + * + * (1..100).grep 38..44 #=> [38, 39, 40, 41, 42, 43, 44] + * c = IO.constants + * c.grep(/SEEK/) #=> ["SEEK_END", "SEEK_SET", "SEEK_CUR"] + * res = c.grep(/SEEK/) {|v| IO.const_get(v) } + * res #=> [2, 0, 1] + * + */ + static VALUE enum_grep(obj, pat) VALUE obj, pat; @@ -72,6 +90,20 @@ find_i(i, memo) return Qnil; } +/* + * call-seq: + * enum.detect {| obj | block } => obj or nil + * enum.find {| obj | block } => obj or nil + * + * Passes each entry in enum to block. Returns the + * first for which block is not false. Returns + * nil if no object matches. + * + * (1..10).detect {|i| i % 5 == 0 and i % 7 == 0 } #=> nil + * (1..100).detect {|i| i % 5 == 0 and i % 7 == 0 } #=> 35 + * + */ + static VALUE enum_find(argc, argv, obj) int argc; @@ -105,6 +137,19 @@ find_all_i(i, ary) return Qnil; } +/* + * call-seq: + * enum.find_all {| obj | block } => array + * enum.select {| obj | block } => array + * + * Returns an array containing all elements of enum for which + * block is not false (see also + * Enumerable#reject). + * + * (1..10).find_all {|i| i % 3 == 0 } #=> [3, 6, 9] + * + */ + static VALUE enum_find_all(obj) VALUE obj; @@ -126,6 +171,17 @@ reject_i(i, ary) return Qnil; } +/* + * call-seq: + * enum.reject {| obj | block } => array + * + * Returns an array for all elements of enum for which + * block is false (see also Enumerable#find_all). + * + * (1..10).reject {|i| i % 3 == 0 } #=> [1, 2, 4, 5, 7, 8, 10] + * + */ + static VALUE enum_reject(obj) VALUE obj; @@ -155,6 +211,19 @@ collect_all(i, ary) return Qnil; } +/* + * call-seq: + * enum.collect {| obj | block } => array + * enum.map {| obj | block } => array + * + * Returns a new array with the results of running block once + * for every element in enum. + * + * (1..4).collect {|i| i*i } #=> [1, 4, 9, 16] + * (1..4).collect { "cat" } #=> ["cat", "cat", "cat", "cat"] + * + */ + static VALUE enum_collect(obj) VALUE obj; @@ -166,6 +235,16 @@ enum_collect(obj) return ary; } +/* + * call-seq: + * enum.to_a => array + * enum.entries => array + * + * Returns an array containing the items in enum. + * + * (1..7).to_a #=> [1, 2, 3, 4, 5, 6, 7] + * { 'a'=>1, 'b'=>2, 'c'=>3 }.to_a #=> [["a", 1], ["b", 2], ["c", 3]] + */ static VALUE enum_to_a(obj) VALUE obj; @@ -192,6 +271,37 @@ inject_i(i, memo) return Qnil; } +/* + * call-seq: + * enum.inject(initial) {| memo, obj | block } => obj + * enum.inject {| 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). + * + * # Sum some numbers + * (5..10).inject {|sum, n| sum + n } #=> 45 + * # Multiply some numbers + * (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 + * + */ + static VALUE enum_inject(argc, argv, obj) int argc; @@ -225,6 +335,18 @@ partition_i(i, ary) return Qnil; } +/* + * call-seq: + * enum.partition {| obj | block } => [ true_array, false_array ] + * + * Returns two arrays, the first containing the elements of + * enum for which the block evaluates to true, the second + * containing the rest. + * + * (1..6).partition {|i| (i&1).zero?} #=> [[2, 4, 6], [1, 3, 5]] + * + */ + static VALUE enum_partition(obj) VALUE obj; @@ -238,6 +360,23 @@ enum_partition(obj) return rb_assoc_new(ary[0], ary[1]); } +/* + * call-seq: + * enum.sort => array + * enum.sort {| a, b | block } => array + * + * Returns an array containing the items in enum sorted, + * either according to their own <=> method, or by using + * the results of the supplied block. The block should return -1, 0, or + * +1 depending on the comparison between a and b. As of + * Ruby 1.8, the method Enumerable#sort_by implements a + * built-in Schwartzian Transform, useful when key computation or + * comparison is expensive.. + * + * %w(rhea kea flea).sort #=> ["flea", "kea", "rhea"] + * (1..10).sort {|a,b| b <=> a} #=> [10, 9, 8, 7, 6, 5, 4, 3, 2, 1] + */ + static VALUE enum_sort(obj) VALUE obj; @@ -267,6 +406,75 @@ sort_by_cmp(a, b) return rb_cmpint(retval, *a, *b); } +/* + * call-seq: + * enum.sort_by {| obj | block } => array + * + * Sorts enum using a set of keys generated by mapping the + * values in enum through the given block. + * + * %w{ apple pear fig }.sort_by {|word| word.length} + #=> ["fig", "pear", "apple"] + * + * The current implementation of sort_by generates an + * array of tuples containing the original collection element and the + * mapped value. This makes sort_by fairly expensive when + * the keysets are simple + * + * require 'benchmark' + * include Benchmark + * + * a = (1..100000).map {rand(100000)} + * + * bm(10) do |b| + * b.report("Sort") { a.sort } + * b.report("Sort by") { a.sort_by {|a| a} } + * end + * + * produces: + * + * user system total real + * Sort 0.180000 0.000000 0.180000 ( 0.175469) + * Sort by 1.980000 0.040000 2.020000 ( 2.013586) + * + * However, consider the case where comparing the keys is a non-trivial + * operation. The following code sorts some files on modification time + * using the basic sort method. + * + * files = Dir["*"] + * sorted = files.sort {|a,b| File.new(a).mtime <=> File.new(b).mtime} + * sorted #=> ["mon", "tues", "wed", "thurs"] + * + * This sort is inefficient: it generates two new File + * objects during every comparison. A slightly better technique is to + * use the Kernel#test method to generate the modification + * times directly. + * + * files = Dir["*"] + * sorted = files.sort { |a,b| + * test(?M, a) <=> test(?M, b) + * } + * sorted #=> ["mon", "tues", "wed", "thurs"] + * + * This still generates many unnecessary Time objects. A + * more efficient technique is to cache the sort keys (modification + * times in this case) before the sort. Perl users often call this + * approach a Schwartzian Transform, after Randal Schwartz. We + * construct a temporary array, where each element is an array + * containing our sort key along with the filename. We sort this array, + * and then extract the filename from the result. + * + * sorted = Dir["*"].collect { |f| + * [test(?M, f), f] + * }.sort.collect { |f| f[1] } + * sorted #=> ["mon", "tues", "wed", "thurs"] + * + * This is exactly what sort_by does internally. + * + * sorted = Dir["*"].sort_by {|f| test(?M, f)} + * sorted #=> ["mon", "tues", "wed", "thurs"] + */ + static VALUE enum_sort_by(obj) VALUE obj; @@ -315,6 +523,23 @@ all_i(i, memo) return Qnil; } +/* + * call-seq: + * enum.all? [{|obj| block } ] => true or false + * + * Passes each element of the collection to the given block. The method + * returns true if the block never returns + * false or nil. If the block is not given, + * Ruby adds an implicit block of {|obj| obj} (that is + * all? will return true only if none of the + * collection members are false or nil.) + * + * %w{ ant bear cat}.all? {|word| word.length >= 3} #=> true + * %w{ ant bear cat}.all? {|word| word.length >= 4} #=> false + * [ nil, true, 99 ].all? #=> false + * + */ + static VALUE enum_all(obj) VALUE obj; @@ -353,6 +578,24 @@ any_i(i, memo) return Qnil; } +/* + * call-seq: + * enum.any? [{|obj| block } ] => true or false + * + * Passes each element of the collection to the given block. The method + * returns true if the block ever returns a value other + * that false or nil. If the block is not + * given, Ruby adds an implicit block of {|obj| obj} (that + * is any? will return true if at least one + * of the collection members is not false or + * nil. + * + * %w{ ant bear cat}.any? {|word| word.length >= 3} #=> true + * %w{ ant bear cat}.any? {|word| word.length >= 4} #=> true + * [ nil, true, 99 ].any? #=> true + * + */ + static VALUE enum_any(obj) VALUE obj; @@ -405,6 +648,21 @@ min_ii(i, memo) return Qnil; } + +/* + * call-seq: + * enum.min => obj + * enum.min {| a,b | block } => obj + * + * Returns the object in enum with the minimum value. The + * first form assumes all objects implement Comparable; + * the second uses the block to return a <=> b. + * + * a = %w(albatross dog horse) + * a.min #=> "albatross" + * a.max {|a,b| a.length <=> b.length } #=> "dog" + */ + static VALUE enum_min(obj) VALUE obj; @@ -418,6 +676,20 @@ enum_min(obj) return result; } +/* + * call-seq: + * enum.max => obj + * enum.max {| a,b | block } => obj + * + * Returns the object in enum with the maximum value. The + * first form assumes all objects implement Comparable; + * the second uses the block to return a <=> b. + * + * a = %w(albatross dog horse) + * a.max #=> "horse" + * a.max {|a,b| a.length <=> b.length } #=> "albatross" + */ + static VALUE max_i(i, memo) VALUE i; @@ -481,6 +753,19 @@ member_i(item, memo) return Qnil; } +/* + * call-seq: + * enum.include?(obj) => true or false + * enum.member?(obj) => true or false + * + * Returns true if any member of enum equals + * obj. Equality is tested using ==. + * + * IO.constants.include? "SEEK_SET" #=> true + * IO.constants.include? "SEEK_NO_FURTHER" #=> false + * + */ + static VALUE enum_member(obj, val) VALUE obj, val; @@ -504,6 +789,21 @@ each_with_index_i(val, memo) return Qnil; } +/* + * call-seq: + * enum.each_with_index {|obj, i| block } -> nil + * + * Calls block with two arguments, the item and its index, for + * each item in enum. + * + * hash = Hash.new + * %w(cat dog wombat).each_with_index {|item, index| + * hash[item] = index + * } + * hash #=> {"cat"=>0, "wombat"=>2, "dog"=>1} + * + */ + static VALUE enum_each_with_index(obj) VALUE obj; @@ -540,6 +840,29 @@ zip_i(val, memo) return Qnil; } +/* + * call-seq: + * enum.zip(arg, ...) => array + * enum.zip(arg, ...) {|arr| block } => nil + * + * Converts any arguments to arrays, then merges elements of + * enum with corresponding elements from each argument. This + * generates a sequence of enum#size n-element + * arrays, where n is one more that the count of arguments. If + * the size of any arguemnt is less than enum#size, + * nil values are supplied. If a block given, it is + * invoked for each output array, otherwise an array of arrays is + * returned. + * + * a = [ 4, 5, 6 ] + * b = [ 7, 8, 9 ] + * + * (1..3).zip(a, b) #=> [[1, 4, 7], [2, 5, 8], [3, 6, 9]] + * "cat\ndog".zip([1]) #=> [["cat\n", 1], ["dog", nil]] + * (1..3).zip #=> [[1], [2], [3]] + * + */ + static VALUE enum_zip(argc, argv, obj) int argc; @@ -560,6 +883,17 @@ enum_zip(argc, argv, obj) return result; } +/* + * The Enumerable mixin provides collection classes with + * several traversal and searching methods, and with the ability to + * sort. The class must provide a method each, which + * yields successive members of the collection. If + * Enumerable#max, #min, or + * #sort is used, the objects in the collection must also + * implement a meaningful <=> operator, as these methods + * rely on an ordering between members of the collection. + */ + void Init_Enumerable() { -- cgit v1.2.3