diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/enumerable.rb')
-rw-r--r-- | activesupport/lib/active_support/core_ext/enumerable.rb | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/activesupport/lib/active_support/core_ext/enumerable.rb b/activesupport/lib/active_support/core_ext/enumerable.rb index 434a32b29b..15a303cf04 100644 --- a/activesupport/lib/active_support/core_ext/enumerable.rb +++ b/activesupport/lib/active_support/core_ext/enumerable.rb @@ -55,12 +55,10 @@ module Enumerable # [].sum(Payment.new(0)) { |i| i.amount } # => Payment.new(0) # def sum(identity = 0, &block) - return identity unless size > 0 - if block_given? - map(&block).sum + map(&block).sum(identity) else - inject { |sum, element| sum + element } + inject { |sum, element| sum + element } || identity end end @@ -113,3 +111,13 @@ module Enumerable !any?(&block) end unless [].respond_to?(:none?) end + +class Range #:nodoc: + # Optimize range sum to use arithmetic progression if a block is not given and + # we have a range of numeric values. + def sum(identity = 0) + return super if block_given? || !(first.instance_of?(Integer) && last.instance_of?(Integer)) + actual_last = exclude_end? ? (last - 1) : last + (actual_last - first + 1) * (actual_last + first) / 2 + end +end |