Module: Enumerable

Defined in:
lib/casual_support/enumerable/index_to.rb,
lib/casual_support/enumerable/duplicates.rb

Instance Method Summary collapse

Instance Method Details

#duplicates ⇒ Enumerable

Returns the first-appearing duplicate of each element, preserving order of appearance.

Examples:

%w[a a b c c b a d].duplicates  # == ["a", "c", "b"]

Returns:



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# File 'lib/casual_support/enumerable/duplicates.rb', line 10

def duplicates
  seen = Hash.new(0)
  self.select{|element| (seen[element] += 1) == 2 }
end

#index_to {|key| ... } ⇒ Hash{key => value}

Creates a Hash using the Enumerable’s elements as keys, and using the given block to compute an associated value for each key.

Examples:

cache = id_list.index_to{|id| find_by_id(id) }

Yields:

  • (key)

Yield Parameters:

  • key (Object)

Yield Returns:

  • (Object) —

    value

Returns:

  • (Hash{key => value}) 


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# File 'lib/casual_support/enumerable/index_to.rb', line 15

def index_to()
  self.reduce({}){|h, k| h.put!(k, (yield k)) }
end