# frozen_string_literal: true module Enumerable INDEX_WITH_DEFAULT = Object.new private_constant :INDEX_WITH_DEFAULT # Enumerable#sum was added in Ruby 2.4, but it only works with Numeric elements # when we omit an identity. # :stopdoc: # 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 # :startdoc: # 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 # Convert an enumerable to a hash keying it by the block return value. # # people.index_by(&:login) # # => { "nextangle" => , "chade-" => , ...} # # people.index_by { |person| "#{person.first_name} #{person.last_name}" } # # => { "Chade- Fowlersburg-e" => , "David Heinemeier Hansson" => , ...} def index_by if block_given? result = {} each { |elem| result[yield(elem)] = elem } result else to_enum(:index_by) { size if respond_to?(:size) } end end # Convert an enumerable to a hash keying it with the enumerable items and with the values returned in the block. # # post = Post.new(title: "hey there", body: "what's up?") # # %i( title body ).index_with { |attr_name| post.public_send(attr_name) } # # => { title: "hey there", body: "what's up?" } def index_with(default = INDEX_WITH_DEFAULT) if block_given? result = {} each { |elem| result[elem] = yield(elem) } result elsif default != INDEX_WITH_DEFAULT result = {} each { |elem| result[elem] = default } result else to_enum(:index_with) { size if respond_to?(:size) } end end # Returns +true+ if the enumerable has more than 1 element. Functionally # equivalent to enum.to_a.size > 1. Can be called with a block too, # much like any?, so people.many? { |p| p.age > 26 } returns +true+ # if more than one person is over 26. def many? cnt = 0 if block_given? any? do |element| cnt += 1 if yield element cnt > 1 end else any? { (cnt += 1) > 1 } end end # Returns a new array that includes the passed elements. # # [ 1, 2, 3 ].including(4, 5) # # => [ 1, 2, 3, 4, 5 ] # # ["David", "Rafael"].including %w[ Aaron Todd ] # # => ["David", "Rafael", "Aaron", "Todd"] def including(*elements) to_a.including(*elements) end # The negative of the Enumerable#include?. Returns +true+ if the # collection does not include the object. def exclude?(object) !include?(object) end # Returns a copy of the enumerable excluding the specified elements. # # ["David", "Rafael", "Aaron", "Todd"].excluding "Aaron", "Todd" # # => ["David", "Rafael"] # # ["David", "Rafael", "Aaron", "Todd"].excluding %w[ Aaron Todd ] # # => ["David", "Rafael"] # # {foo: 1, bar: 2, baz: 3}.excluding :bar # # => {foo: 1, baz: 3} def excluding(*elements) elements.flatten!(1) reject { |element| elements.include?(element) } end # Alias for #excluding. def without(*elements) excluding(*elements) end # Convert an enumerable to an array based on the given key. # # [{ name: "David" }, { name: "Rafael" }, { name: "Aaron" }].pluck(:name) # # => ["David", "Rafael", "Aaron"] # # [{ id: 1, name: "David" }, { id: 2, name: "Rafael" }].pluck(:id, :name) # # => [[1, "David"], [2, "Rafael"]] def pluck(*keys) if keys.many? map { |element| keys.map { |key| element[key] } } else map { |element| element[keys.first] } end end # Returns a new +Array+ without the blank items. # Uses Object#blank? for determining if an item is blank. # # [1, "", nil, 2, " ", [], {}, false, true].compact_blank # # => [1, 2, true] # # Set.new([nil, "", 1, 2]) # # => [2, 1] (or [1, 2]) # # When called on a +Hash+, returns a new +Hash+ without the blank values. # # { a: "", b: 1, c: nil, d: [], e: false, f: true }.compact_blank # #=> { b: 1, f: true } def compact_blank reject(&:blank?) end end class Hash # Hash#reject has its own definition, so this needs one too. def compact_blank #:nodoc: reject { |_k, v| v.blank? } end # Removes all blank values from the +Hash+ in place and returns self. # Uses Object#blank? for determining if a value is blank. # # h = { a: "", b: 1, c: nil, d: [], e: false, f: true } # h.compact_blank! # # => { b: 1, f: true } def compact_blank! # use delete_if rather than reject! because it always returns self even if nothing changed delete_if { |_k, v| v.blank? } end 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 = 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 sum = identity || 0 sum + (actual_last - first + 1) * (actual_last + first) / 2 else identity || 0 end end end end # Using Refinements here in order not to expose our internal method using Module.new { refine Array do alias :orig_sum :sum end } class Array #:nodoc: # Array#sum was added in Ruby 2.4 but it only works with Numeric elements. def sum(init = nil, &block) if init.is_a?(Numeric) || first.is_a?(Numeric) init ||= 0 orig_sum(init, &block) else super end end # Removes all blank elements from the +Array+ in place and returns self. # Uses Object#blank? for determining if an item is blank. # # a = [1, "", nil, 2, " ", [], {}, false, true] # a.compact_blank! # # => [1, 2, true] def compact_blank! # use delete_if rather than reject! because it always returns self even if nothing changed delete_if(&:blank?) end end