1.9.2: Implement Array#repeated_combination, #repeated_permutation (v…

… 1.17.0)

CHANGELOG.rdoc

@@ -1,8 +1,14 @@
 = Packable --- History
 
+== Version 1.17.0 - May 17th, 2010
+
+* Added some features of 1.9.2:
+
+  * Array#repeated_combination, #repeated_permutation
+
 == Version 1.16.2 - April 11th, 2010
 
-* Added a features of 1.9.2:
+* Added some features of 1.9.2:
 
   * Array#uniq, #uniq! (with block)
   * Array#product (with block)

README.rdoc

@@ -110,6 +110,7 @@ but since it is only an imitation, it must be required explicitly:
   * <tt>rotate, rotate!</tt>
   * <tt>keep_if, select!</tt>
   * +product+ (with block)
+  * +repeated_combination+, +repeated_permutation+
   * <tt>sort_by!</tt>
   * <tt>uniq, #uniq!</tt> (with block)
 

VERSION.yml

@@ -1,5 +1,5 @@
 --- 
 :major: 1
+:minor: 17
+:patch: 0
 :build: 
-:minor: 16
-:patch: 7

backports.gemspec

@@ -5,11 +5,11 @@
 
 Gem::Specification.new do |s|
   s.name = %q{backports}
-  s.version = "1.16.7"
+  s.version = "1.17.0"
 
   s.required_rubygems_version = Gem::Requirement.new(">= 0") if s.respond_to? :required_rubygems_version=
   s.authors = ["Marc-Andr\303\251 Lafortune"]
-  s.date = %q{2010-05-03}
+  s.date = %q{2010-05-17}
   s.description = %q{      Essential backports that enable some of the really nice features of ruby 1.8.7, ruby 1.9 and rails from ruby 1.8.6 and earlier.
 }
   s.email = %q{github@marc-andre.ca}

lib/backports/1.9.2/array.rb

@@ -27,6 +27,43 @@ def product_with_block(*arg, &block)
     Backports.alias_method_chain self, :product, :block
   end
 
+  # Note: Combinations are not yielded in the same order as MRI.
+  # This is not a bug; the spec states that the order is implementation dependent
+  def repeated_combination(num, &block)
+    return to_enum :repeated_combination, num unless block_given?
+    num = Backports.coerce_to_int(num)
+    if num <= 0
+      yield [] if num == 0
+    else
+      indices = Array.new(num, 0)
+      indices[-1] = size
+      while dec = indices.find_index(&:nonzero?)
+        indices[0..dec] = Array.new dec+1, indices[dec]-1
+        yield values_at(*indices)
+      end
+    end
+    self
+  end unless method_defined? :repeated_combination
+
+  # Note: Permutations are not yielded in the same order as MRI.
+  # This is not a bug; the spec states that the order is implementation dependent
+  def repeated_permutation(num, &block)
+    return to_enum :repeated_permutation, num unless block_given?
+    num = Backports.coerce_to_int(num)
+    if num <= 0
+      yield [] if num == 0
+    else
+      indices = Array.new(num, 0)
+      indices[-1] = size
+      while dec = indices.find_index(&:nonzero?)
+        indices[0...dec] = Array.new dec, size-1
+        indices[dec] -= 1
+        yield values_at(*indices)
+      end
+    end
+    self
+  end unless method_defined? :repeated_permutation
+
   def rotate(n=1)
     dup.rotate!(n)
   end unless method_defined? :rotate