constants | attributes | methods
Class

Generator

Inheritance
< Object
Included Modules
Enumerable

Generator converts an internal iterator (i.e. an Enumerable object) to an external iterator.

Note that it is not very fast since it is implemented using continuations, which are currently slow.

Example

  require 'generator'

  # Generator from an Enumerable object
  g = Generator.new(['A', 'B', 'C', 'Z'])

  while g.next?
    puts g.next
  end

  # Generator from a block
  g = Generator.new { |g|
    for i in 'A'..'C'
      g.yield i
    end

    g.yield 'Z'
  }

  # The same result as above
  while g.next?
    puts g.next
  end

Methods

Class

Visibility Signature
public new (enum = nil, &block)

Instance

Visibility Signature
public current ()
public each () {|self.next| ...}
public end? ()
public index ()
public next ()
public next? ()
public pos ()
public rewind ()
public yield (value)

Class Method Detail

new(enum = nil, &block)

Creates a new generator either from an Enumerable object or from a block.

In the former, block is ignored even if given.

In the latter, the given block is called with the generator itself, and expected to call the yield method for each element.

Instance Method Detail

current()

Returns the element at the current position.

each() {|self.next| ...}

Rewinds the generator and enumerates the elements.

end?()

Returns true if the generator has reached the end.

index()

Returns the current index (position) counting from zero.

next()

Returns the element at the current position and moves forward.

next?()

Returns true if the generator has not reached the end yet.

pos()

Returns the current index (position) counting from zero.

rewind()

Rewinds the generator.

yield(value)

Yields an element to the generator.