diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/enumerable.rb')
| -rw-r--r-- | activesupport/lib/active_support/core_ext/enumerable.rb | 95 |
1 files changed, 63 insertions, 32 deletions
diff --git a/activesupport/lib/active_support/core_ext/enumerable.rb b/activesupport/lib/active_support/core_ext/enumerable.rb index 9a893157ea..17733d955c 100644 --- a/activesupport/lib/active_support/core_ext/enumerable.rb +++ b/activesupport/lib/active_support/core_ext/enumerable.rb @@ -1,40 +1,66 @@ +# frozen_string_literal: true + module Enumerable - # Calculates a sum from the elements. - # - # payments.sum { |p| p.price * p.tax_rate } - # payments.sum(&:price) - # - # The latter is a shortcut for: - # - # payments.inject(0) { |sum, p| sum + p.price } - # - # It can also calculate the sum without the use of a block. + # Enumerable#sum was added in Ruby 2.4, but it only works with Numeric elements + # when we omit an identity. # - # [5, 15, 10].sum # => 30 - # ['foo', 'bar'].sum # => "foobar" - # [[1, 2], [3, 1, 5]].sum => [1, 2, 3, 1, 5] - # - # 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 = nil, &block) - if block_given? - map(&block).sum(identity) - else - sum = identity ? inject(identity, :+) : inject(:+) - sum || identity || 0 + # 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 Enumerable.instance_methods(false).include?(:sum) && !((?a..?b).sum rescue false) + # We can't use Refinements here because Refinements with Module which will be prepended + # doesn't work well https://bugs.ruby-lang.org/issues/13446 + alias :_original_sum_with_required_identity :sum + private :_original_sum_with_required_identity + # Calculates a sum from the elements. + # + # payments.sum { |p| p.price * p.tax_rate } + # payments.sum(&:price) + # + # The latter is a shortcut for: + # + # payments.inject(0) { |sum, p| sum + p.price } + # + # It can also calculate the sum without the use of a block. + # + # [5, 15, 10].sum # => 30 + # ['foo', 'bar'].sum # => "foobar" + # [[1, 2], [3, 1, 5]].sum # => [1, 2, 3, 1, 5] + # + # 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 = nil, &block) + if identity + _original_sum_with_required_identity(identity, &block) + elsif block_given? + map(&block).sum(identity) + else + inject(:+) || 0 + end + end + else + def sum(identity = nil, &block) + if block_given? + map(&block).sum(identity) + else + sum = identity ? inject(identity, :+) : inject(:+) + sum || identity || 0 + end end end # Convert an enumerable to a hash. # # people.index_by(&:login) - # => { "nextangle" => <Person ...>, "chade-" => <Person ...>, ...} + # # => { "nextangle" => <Person ...>, "chade-" => <Person ...>, ...} # people.index_by { |person| "#{person.first_name} #{person.last_name}" } - # => { "Chade- Fowlersburg-e" => <Person ...>, "David Heinemeier Hansson" => <Person ...>, ...} + # # => { "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 @@ -65,10 +91,10 @@ module Enumerable # Returns a copy of the enumerable without the specified elements. # # ["David", "Rafael", "Aaron", "Todd"].without "Aaron", "Todd" - # => ["David", "Rafael"] + # # => ["David", "Rafael"] # # {foo: 1, bar: 2, baz: 3}.without :bar - # => {foo: 1, baz: 3} + # # => {foo: 1, baz: 3} def without(*elements) reject { |element| elements.include?(element) } end @@ -76,10 +102,10 @@ module Enumerable # Convert an enumerable to an array based on the given key. # # [{ name: "David" }, { name: "Rafael" }, { name: "Aaron" }].pluck(:name) - # => ["David", "Rafael", "Aaron"] + # # => ["David", "Rafael", "Aaron"] # # [{ id: 1, name: "David" }, { id: 2, name: "Rafael" }].pluck(:id, :name) - # => [[1, "David"], [2, "Rafael"]] + # # => [[1, "David"], [2, "Rafael"]] def pluck(*keys) if keys.many? map { |element| keys.map { |key| element[key] } } @@ -113,9 +139,14 @@ end # 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 + # Using Refinements here in order not to expose our internal method + using Module.new { + refine Array do + alias :orig_sum :sum + end + } + class Array def sum(init = nil, &block) #:nodoc: if init.is_a?(Numeric) || first.is_a?(Numeric) init ||= 0 |