Class: Pupa::Processor::Yielder

Inherits:
Object
  • Object
show all
Defined in:
lib/pupa/processor/yielder.rb

Overview

A lazy enumerator.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Yielder

The given block should yield objects to add to the enumerator.



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# File 'lib/pupa/processor/yielder.rb', line 10

def initialize
  @fiber = Fiber.new do
    yield
    raise StopIteration
  end
end

Instance Method Details

#each ⇒ Object

Yields each object in the enumerator to the given block.



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# File 'lib/pupa/processor/yielder.rb', line 18

def each
  if block_given?
    loop do
      yield self.next
    end
  else
    to_enum
  end
end

#next ⇒ Object

Returns the next object in the enumerator, and moves the internal position forward. When the position reaches the end, StopIteration is raised.



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# File 'lib/pupa/processor/yielder.rb', line 30

def next
  if @fiber.alive?
    @fiber.resume
  else
    raise StopIteration
  end
end

#to_enum ⇒ Enumerator

Returns a lazy enumerator.

Returns:

  • (Enumerator) —

    a lazy enumerator



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# File 'lib/pupa/processor/yielder.rb', line 41

def to_enum
  Enumerator.new do |y|
    loop do
      y << self.next
    end
  end
end