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| author | David Heinemeier Hansson <david@loudthinking.com> | 2006-06-24 16:14:59 +0000 |
|---|---|---|
| committer | David Heinemeier Hansson <david@loudthinking.com> | 2006-06-24 16:14:59 +0000 |
| commit | fd0eaaa407fb8fd704967be2734c1b094ac630d9 (patch) | |
| tree | e6b8d271e1f70ab38a15faafde16f80abd6e1322 /activesupport/lib/active_support/core_ext/enumerable.rb | |
| parent | 8b89bd779a1ddc78da63de295574b8519c3e94c8 (diff) | |
| download | rails-fd0eaaa407fb8fd704967be2734c1b094ac630d9.tar.gz rails-fd0eaaa407fb8fd704967be2734c1b094ac630d9.tar.bz2 rails-fd0eaaa407fb8fd704967be2734c1b094ac630d9.zip | |
Added Enumerable#sum for calculating a sum from the elements [DHH]
git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4489 5ecf4fe2-1ee6-0310-87b1-e25e094e27de
Diffstat (limited to 'activesupport/lib/active_support/core_ext/enumerable.rb')
| -rw-r--r-- | activesupport/lib/active_support/core_ext/enumerable.rb | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/activesupport/lib/active_support/core_ext/enumerable.rb b/activesupport/lib/active_support/core_ext/enumerable.rb index 5c556ff98d..4de520f4ed 100644 --- a/activesupport/lib/active_support/core_ext/enumerable.rb +++ b/activesupport/lib/active_support/core_ext/enumerable.rb @@ -1,3 +1,5 @@ +require File.dirname(__FILE__) + '/enumerable/injections' + module Enumerable #:nodoc: # Collect an enumerable into sets, grouped by the result of a block. Useful, # for example, for grouping records by date. @@ -20,4 +22,14 @@ module Enumerable #:nodoc: groups end end -end + + # Calculates a sum from the elements. Examples: + # + # payments.sum { |p| p.price * p.tax_rate } + # payments.sum(&:price) + # + # This is instead of payments.inject(0) { |sum, p| sum + p.price } + def sum + inject(0) { |sum, element| sum + yield(element) } + end +end
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