Module: Enumerable
Relationships & Source Files | |
Namespace Children | |
Exceptions:
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Extension / Inclusion / Inheritance Descendants | |
Included In:
ActionController::MiddlewareStack,
ActionController::RequestForgeryProtection::ProtectionMethods::NullSession::NullCookieJar,
ActionDispatch::Cookies::CookieJar,
::ActionDispatch::Flash::FlashHash ,
::ActionDispatch::Http::Headers ,
ActionDispatch::Journey::Nodes::Binary,
ActionDispatch::Journey::Nodes::Cat,
ActionDispatch::Journey::Nodes::Dot,
ActionDispatch::Journey::Nodes::Dummy,
ActionDispatch::Journey::Nodes::Group,
ActionDispatch::Journey::Nodes::Literal,
ActionDispatch::Journey::Nodes::Node,
ActionDispatch::Journey::Nodes::Or,
ActionDispatch::Journey::Nodes::Slash,
ActionDispatch::Journey::Nodes::Star,
ActionDispatch::Journey::Nodes::Symbol,
ActionDispatch::Journey::Nodes::Terminal,
ActionDispatch::Journey::Nodes::Unary,
ActionDispatch::Journey::Routes,
::ActionDispatch::MiddlewareStack ,
ActionDispatch::Routing::Mapper::Scope,
ActionDispatch::Routing::RouteSet::NamedRouteCollection,
ActionView::CollectionRenderer::CollectionIterator,
ActionView::CollectionRenderer::MixedCollectionIterator,
ActionView::CollectionRenderer::PreloadCollectionIterator,
ActionView::CollectionRenderer::SameCollectionIterator,
ActionView::PathSet,
::ActiveModel::Errors ,
ActiveRecord::AssociationRelation,
::ActiveRecord::Associations::CollectionProxy ,
ActiveRecord::Associations::JoinDependency::JoinAssociation,
ActiveRecord::Associations::JoinDependency::JoinBase,
ActiveRecord::Associations::JoinDependency::JoinPart,
::ActiveRecord::Batches::BatchEnumerator ,
ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter::StatementPool,
ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::StatementPool,
ActiveRecord::ConnectionAdapters::SQLite3Adapter::StatementPool,
ActiveRecord::ConnectionAdapters::StatementPool,
ActiveRecord::DisableJoinsAssociationRelation,
ActiveRecord::Fixture,
ActiveRecord::FixtureSet::File,
::ActiveRecord::Relation ,
::ActiveRecord::Result ,
ActiveSupport::Callbacks::CallbackChain,
ActiveSupport::DescendantsTracker::DescendantsArray,
::Mime::Mimes ,
Rails::Autoloaders,
::Rails::Engine::Railties ,
::Rails::Paths::Path
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Super Chains via Extension / Inclusion / Inheritance | |
Instance Chain:
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Defined in: | activesupport/lib/active_support/core_ext/enumerable.rb, activesupport/lib/active_support/core_ext/object/json.rb |
Instance Attribute Summary
-
#many? ⇒ Boolean
readonly
Returns
true
if the enumerable has more than 1 element.
Instance Method Summary
-
#compact_blank
Returns a new
::Array
without the blank items. -
#exclude?(object) ⇒ Boolean
The negative of the
Enumerable#include?
. -
#excluding(*elements)
(also: #without)
Returns a copy of the enumerable excluding the specified elements.
-
#in_order_of(key, series)
Returns a new
::Array
where the order has been set to that provided in theseries
, based on thekey
of the objects in the original enumerable. -
#including(*elements)
Returns a new array that includes the passed elements.
-
#index_by
Convert an enumerable to a hash, using the block result as the key and the element as the value.
-
#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.
-
#maximum(key)
Calculates the maximum from the extracted elements.
-
#minimum(key)
Calculates the minimum from the extracted elements.
-
#pick(*keys)
Extract the given key from the first element in the enumerable.
-
#pluck(*keys)
Extract the given key from each element in the enumerable.
-
#sole
Returns the sole item in the enumerable.
-
#without(*elements)
Alias for #excluding.
Instance Attribute Details
#many? ⇒ Boolean
(readonly)
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.
# 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
Instance Method Details
#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 }
# File 'activesupport/lib/active_support/core_ext/enumerable.rb', line 184
def compact_blank reject(&:blank?) end
#exclude?(object) ⇒ Boolean
The negative of the Enumerable#include?
. Returns true
if the collection does not include the object.
# File 'activesupport/lib/active_support/core_ext/enumerable.rb', line 118
def exclude?(object) !include?(object) end
#excluding(*elements) Also known 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 :
# => {foo: 1, baz: 3}
# 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)
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.
# File 'activesupport/lib/active_support/core_ext/enumerable.rb', line 196
def in_order_of(key, series) group_by(&key).values_at(*series).flatten(1).compact 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"]
# 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 ...>, ...}
# 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 }
# 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
#maximum(key)
Calculates the maximum from the extracted elements.
payments = [Payment.new(5), Payment.new(15), Payment.new(10)]
payments.maximum(:price) # => 15
# 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
# 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"]
# 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"]]
# 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
# File 'activesupport/lib/active_support/core_ext/enumerable.rb', line 206
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.
# File 'activesupport/lib/active_support/core_ext/enumerable.rb', line 136
alias :without :excluding