Added Array#to_s(:db) that'll produce a comma-separated list of ids [DHH] Split Grouping into its own file

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4387 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 46 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/core_ext/array/grouping.rb b/activesupport/lib/active_support/core_ext/array/grouping.rb
new file mode 100644
index 0000000000..6f28e1eb6d
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/array/grouping.rb
@@ -0,0 +1,46 @@
+module ActiveSupport #:nodoc:
+  module CoreExtensions #:nodoc:
+    module Array #:nodoc:
+      module Grouping
+        # Iterate over an array in groups of a certain size, padding any remaining 
+        # slots with specified value (<tt>nil</tt> by default).
+        # 
+        # E.g.
+        # 
+        #   %w(1 2 3 4 5 6 7).in_groups_of(3) {|g| p g}
+        #   ["1", "2", "3"]
+        #   ["4", "5", "6"]
+        #   ["7", nil, nil]
+        def in_groups_of(number, fill_with = nil, &block)
+          require 'enumerator'
+          collection = dup
+          collection << fill_with until collection.size.modulo(number).zero?
+          grouped_collection = [] unless block_given?
+          collection.each_slice(number) do |group|
+            block_given? ? yield(group) : grouped_collection << group
+          end
+          grouped_collection unless block_given?
+        end
+
+        # Divide the array into one or more subarrays based on a delimiting +value+
+        # or the result of an optional block.
+        #
+        # ex.
+        #
+        #   [1, 2, 3, 4, 5].split(3)                # => [[1, 2], [4, 5]]
+        #   (1..10).to_a.split { |i| i % 3 == 0 }   # => [[1, 2], [4, 5], [7, 8], [10]]
+        def split(value = nil, &block)
+          block ||= Proc.new { |e| e == value }
+          inject([[]]) do |results, element|
+            if block.call(element)
+              results << []
+            else
+              results.last << element
+            end
+            results
+          end
+        end
+      end
+    end
+  end
+end