diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/enumerable.rb')
-rw-r--r-- | activesupport/lib/active_support/core_ext/enumerable.rb | 36 |
1 files changed, 30 insertions, 6 deletions
diff --git a/activesupport/lib/active_support/core_ext/enumerable.rb b/activesupport/lib/active_support/core_ext/enumerable.rb index fc7531d088..8ebe758078 100644 --- a/activesupport/lib/active_support/core_ext/enumerable.rb +++ b/activesupport/lib/active_support/core_ext/enumerable.rb @@ -17,11 +17,12 @@ module Enumerable # The default sum of an empty list is zero. You can override this default: # # [].sum(Payment.new(0)) { |i| i.amount } # => Payment.new(0) - def sum(identity = 0, &block) + def sum(identity = nil, &block) if block_given? map(&block).sum(identity) else - inject { |sum, element| sum + element } || identity + sum = identity ? inject(identity, :+) : inject(:+) + sum || identity || 0 end end @@ -33,7 +34,9 @@ module Enumerable # => { "Chade- Fowlersburg-e" => <Person ...>, "David Heinemeier Hansson" => <Person ...>, ...} def index_by if block_given? - Hash[map { |elem| [yield(elem), elem] }] + result = {} + each { |elem| result[yield(elem)] = elem } + result else to_enum(:index_by) { size if respond_to?(:size) } end @@ -91,15 +94,36 @@ 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) + def sum(identity = nil) if block_given? || !(first.is_a?(Integer) && last.is_a?(Integer)) super else actual_last = exclude_end? ? (last - 1) : last if actual_last >= first - (actual_last - first + 1) * (actual_last + first) / 2 + sum = identity || 0 + sum + (actual_last - first + 1) * (actual_last + first) / 2 else - identity + identity || 0 + end + end + end +end + +# Array#sum was added in Ruby 2.4 but it only works with Numeric elements. +# +# We tried shimming it to attempt the fast native method, rescue TypeError, +# and fall back to the compatible implementation, but that's much slower than +# just calling the compat method in the first place. +if Array.instance_methods(false).include?(:sum) && !(%w[a].sum rescue false) + class Array + alias :orig_sum :sum + + def sum(init = nil, &block) #:nodoc: + if init.is_a?(Numeric) || first.is_a?(Numeric) + init ||= 0 + orig_sum(init, &block) + else + super end end end |