Module: Denumerable

Included in:
Denumerator
Defined in:
lib/core/facets/denumerable.rb

Overview

Classes which include Denumerable will get versions of map, select, and so on, which return a Denumerator, so that they work horizontally without creating intermediate arrays.

Author:

  • Brian Candler

  • Trans

Instance Method Summary collapse

Instance Method Details

#map ⇒ Object Also known as: collect 



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# File 'lib/core/facets/denumerable.rb', line 11

def map
  Denumerator.new do |output|
    each do |*input|
      output.yield yield(*input)
    end
  end
end

#reject ⇒ Object 



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# File 'lib/core/facets/denumerable.rb', line 31

def reject
  Denumerator.new do |output|
    each do |*input|
      output.yield(*input) unless yield(*input)
    end
  end
end

#select ⇒ Object Also known as: find_all 



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# File 'lib/core/facets/denumerable.rb', line 21

def select
  Denumerator.new do |output|
    each do |*input|
      output.yield(*input) if yield(*input)
    end
  end
end

#skip(n) ⇒ Object

Skip the first n items in the list



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# File 'lib/core/facets/denumerable.rb', line 52

def skip(n)
  Denumerator.new do |output|
    count = 0
    each do |*input|
      output.yield(*input) if count >= n
      count += 1
    end
  end
end

#take(n) ⇒ Object

Limit to the first n items in the list



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# File 'lib/core/facets/denumerable.rb', line 40

def take(n)
  Denumerator.new do |output|
    count = 0
    each do |*input|
      break if count >= n
      output.yield(*input)
      count += 1
    end
  end
end