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Clarify Array#in_groups_of implementation, don't dup unless needed, o…

…nly require enumerator once.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8161 5ecf4fe2-1ee6-0310-87b1-e25e094e27de
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1 parent bff2172 commit 129b3bdcead4c3cd5999a0069d2e13e4e5a043bf @jeremy jeremy committed Nov 17, 2007
Showing with 20 additions and 7 deletions.
  1. +20 −7 activesupport/lib/active_support/core_ext/array/grouping.rb
@@ -1,3 +1,5 @@
+require 'enumerator'
+
module ActiveSupport #:nodoc:
module CoreExtensions #:nodoc:
module Array #:nodoc:
@@ -21,14 +23,23 @@ module Grouping
# ["1", "2"]
# ["3"]
def in_groups_of(number, fill_with = nil, &block)
- require 'enumerator'
- collection = dup
- collection << fill_with until collection.size.modulo(number).zero? unless fill_with == false
- grouped_collection = [] unless block_given?
- collection.each_slice(number) do |group|
- block_given? ? yield(group) : grouped_collection << group
+ if fill_with == false
+ collection = self
+ else
+ # size % number gives how many extra we have;
+ # subtracting from number gives how many to add;
+ # modulo number ensures we don't add group of just fill.
+ padding = (number - size % number) % number
+ collection = dup.concat([fill_with] * padding)
+ end
+
+ if block_given?
+ collection.each_slice(number, &block)
+ else
+ returning [] do |groups|
+ collection.each_slice(number) { |group| groups << group }
+ end
end
- grouped_collection unless block_given?
end
# Divide the array into one or more subarrays based on a delimiting +value+
@@ -40,12 +51,14 @@ def in_groups_of(number, fill_with = nil, &block)
# (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

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