Class: SyncEnumerator

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/generator.rb

Overview

SyncEnumerator creates an Enumerable object from multiple Enumerable objects and enumerates them synchronously.

Example

require 'generator'

s = SyncEnumerator.new([1,2,3], ['a', 'b', 'c'])

# Yields [1, 'a'], [2, 'b'], and [3,'c']
s.each { |row| puts row.join(', ') }

Instance Method Summary collapse

Constructor Details

#initialize(*enums) ⇒ SyncEnumerator

Creates a new SyncEnumerator which enumerates rows of given Enumerable objects.



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# File 'lib/generator.rb', line 224

def initialize(*enums)
  @gens = enums.map { |e| Generator.new(e) }
end

Instance Method Details

#each ⇒ Object

Enumerates rows of the Enumerable objects.



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# File 'lib/generator.rb', line 252

def each
  @gens.each { |g| g.rewind }

  loop do
    count = 0

    ret = @gens.map { |g|
	if g.end?
 count += 1
 nil
	else
 g.next
	end
    }

    if count == @gens.size
	break
    end

    yield ret
  end

  self
end

#end?(i = nil) ⇒ Boolean

Returns true if the given nth Enumerable object has reached the end. If no argument is given, returns true if any of the Enumerable objects has reached the end.

Returns:

  • (Boolean) 


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# File 'lib/generator.rb', line 243

def end?(i = nil)
  if i.nil?
    @gens.detect { |g| g.end? } ? true : false
  else
    @gens[i].end?
  end
end

#length ⇒ Object

Returns the number of enumerated Enumerable objects, i.e. the size of each row.



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# File 'lib/generator.rb', line 236

def length
  @gens.length
end

#size ⇒ Object

Returns the number of enumerated Enumerable objects, i.e. the size of each row.



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# File 'lib/generator.rb', line 230

def size
  @gens.size
end