class Spruz::Generator
This class can create generator objects, that can produce all tuples, that would be created by as many for-loops as dimensions were given.
The generator
g = Spruz::Generator[1..2, %w[a b c]]
produces
g.to_a # => [[1, "a"], [1, "b"], [1, "c"], [2, "a"], [2, "b"], [2, "c"]]
The 'each' method can be used to iterate over the tuples
g.each { |a, b| puts "#{a} #{b}" }
and Spruz::Generator includes the Enumerable module, so Enumerable.instance_methods can be used as well:
g.select { |a, b| %w[a c].include? b } # => [[1, "a"], [1, "c"], [2, "a"], [2, "c"]]
Public Class Methods
Create a new Generator object from the enumberables enums.
# File lib/spruz/generator.rb, line 20 def self.[](*enums) new(enums) end
Create a new Generator instance. Use the objects in the Array enums as dimensions. The should all respond to the :each method (see module Enumerable in the core ruby library).
# File lib/spruz/generator.rb, line 27 def initialize(enums) @enums, @iterators, @n = [], [], 0 enums.each { |e| add_dimension(e) } end
Public Instance Methods
Add another dimension to this generator. enum is an object, that ought to respond to the iterator method (defaults to :each).
# File lib/spruz/generator.rb, line 55 def add_dimension(enum, iterator = :each) @enums << enum @iterators << iterator @n += 1 end
Iterate over all tuples produced by this generator and yield to them.
# File lib/spruz/generator.rb, line 33 def each(&block) # :yield: tuple recurse(&block) self end
Return the size of this generator, that is the number of its dimensions.
# File lib/spruz/generator.rb, line 62 def size @enums.size end
Private Instance Methods
# File lib/spruz/generator.rb, line 38 def recurse(tuple = [ nil ] * @n, i = 0, &block) if i < @n - 1 then @enums[i].__send__(@iterators[i]) do |x| tuple[i] = x recurse(tuple, i + 1, &block) end else @enums[i].__send__(@iterators[i]) do |x| tuple[i] = x yield tuple.dup end end end