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module Enumerable

Public instance methods

compact_blank()

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, false]).compact_blank
# => [1]

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 }
Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 184
def compact_blank
  reject(&:blank?)
end

exclude?(object)

The negative of the Enumerable#include?. Returns true if the collection does not include the object.

Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 118
def exclude?(object)
  !include?(object)
end

excluding(*elements)

Also aliased as: without.

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}
Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 132
def excluding(*elements)
  elements.flatten!(1)
  reject { |element| elements.include?(element) }
end

in_order_of(key, series, filter: true)

Returns a new Array where the order has been set to that provided in the series, based on the key of the objects in the original enumerable.

[ Person.find(5), Person.find(3), Person.find(1) ].in_order_of(:id, [ 1, 5, 3 ])
# => [ Person.find(1), Person.find(5), Person.find(3) ]

If the series include keys that have no corresponding element in the Enumerable, these are ignored. If the Enumerable has additional elements that aren’t named in the series, these are not included in the result, unless the filter option is set to false.

Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 197
def in_order_of(key, series, filter: true)
  if filter
    group_by(&key).values_at(*series).flatten(1).compact
  else
    sort_by { |v| series.index(v.public_send(key)) || series.size }.compact
  end
end

including(*elements)

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"]
Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 112
def including(*elements)
  to_a.including(*elements)
end

index_by()

Convert an enumerable to a hash, using the block result as the key and the element as the value.

people.index_by(&:login)
# => { "nextangle" => <Person ...>, "chade-" => <Person ...>, ...}

people.index_by { |person| "#{person.first_name} #{person.last_name}" }
# => { "Chade- Fowlersburg-e" => <Person ...>, "David Heinemeier Hansson" => <Person ...>, ...}
Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 52
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

index_with(default = (no_default = true))

Convert an enumerable to a hash, using the element as the key and the block result as the value.

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?" }

If an argument is passed instead of a block, it will be used as the value for all elements:

%i( created_at updated_at ).index_with(Time.now)
# => { created_at: 2020-03-09 22:31:47, updated_at: 2020-03-09 22:31:47 }
Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 75
def index_with(default = (no_default = true))
  if block_given?
    result = {}
    each { |elem| result[elem] = yield(elem) }
    result
  elsif no_default
    to_enum(:index_with) { size if respond_to?(:size) }
  else
    result = {}
    each { |elem| result[elem] = default }
    result
  end
end

many?()

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.

Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 93
def many?
  cnt = 0
  if block_given?
    any? do |*args|
      cnt += 1 if yield(*args)
      cnt > 1
    end
  else
    any? { (cnt += 1) > 1 }
  end
end

maximum(key)

Calculates the maximum from the extracted elements.

payments = [Payment.new(5), Payment.new(15), Payment.new(10)]
payments.maximum(:price) # => 15
Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 40
def maximum(key)
  map(&key).max
end

minimum(key)

Calculates the minimum from the extracted elements.

payments = [Payment.new(5), Payment.new(15), Payment.new(10)]
payments.minimum(:price) # => 5
Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 32
def minimum(key)
  map(&key).min
end

pick(*keys)

Extract the given key from the first element in the enumerable.

[{ name: "David" }, { name: "Rafael" }, { name: "Aaron" }].pick(:name)
# => "David"

[{ id: 1, name: "David" }, { id: 2, name: "Rafael" }].pick(:id, :name)
# => [1, "David"]
Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 161
def pick(*keys)
  return if none?

  if keys.many?
    keys.map { |key| first[key] }
  else
    first[keys.first]
  end
end

pluck(*keys)

Extract the given key from each element in the enumerable.

[{ 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"]]
Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 145
def pluck(*keys)
  if keys.many?
    map { |element| keys.map { |key| element[key] } }
  else
    key = keys.first
    map { |element| element[key] }
  end
end

sole()

Returns the sole item in the enumerable. If there are no items, or more than one item, raises Enumerable::SoleItemExpectedError.

["x"].sole          # => "x"
Set.new.sole        # => Enumerable::SoleItemExpectedError: no item found
{ a: 1, b: 2 }.sole # => Enumerable::SoleItemExpectedError: multiple items found
Source code GitHub 
# File activesupport/lib/active_support/core_ext/enumerable.rb, line 211
def sole
  case count
  when 1   then return first # rubocop:disable Style/RedundantReturn
  when 0   then raise ActiveSupport::EnumerableCoreExt::SoleItemExpectedError, "no item found"
  when 2.. then raise ActiveSupport::EnumerableCoreExt::SoleItemExpectedError, "multiple items found"
  end
end

without(*elements)

Alias for: excluding.

Namespace

Definition files