lib/cartesian.rb in Cartesian-0.4.1 vs lib/cartesian.rb in Cartesian-0.4.2

@@ -1,161 +1 @@
-#
-# The CartesianProduct module provide methods for the calculation
-# of the cartesian producted between two enumberable objects.
-#
-# It can also be easily mixed in into any enumberable class,
-# i.e. any class with Enumerable module mixed in.
-# Notice that the names of the methods for mixin are different.
-#
-# Module:
-#   Cartesian::product(foo, bar)
-#
-# Mixin:
-#   foo.cartesian( bar )
-#
-# The module is automatically mixed in Array class.
-#
-# == Author
-# Adriano MITRE <[e-mail]>
-#
-# == Example
-#
-# as module
-#   require 'cartesian'
-#   foo = [1, 2]
-#   bar = ["a", "b"]
-#   Cartesian::product(foo, bar) #=> [[1, "a"], [1, "b"], [2, "a"], [2, "b"]]
-# as mixin
-#   require 'cartesian'
-#   foo = [1, 2]
-#   bar = ["a", "b"]
-#   foo.cartesian(bar)  #=> [[1, "a"], [1, "b"], [2, "a"], [2, "b"]]
-#
-
-require 'cartesian_iterator'
-
-module Cartesian
-
-  # Produces the cartesian product of self and other.
-  # The result is an array of pairs (i.e. two-element arrays).
-  #
-  #   Cartesian::product( [1,2], %w(A B) ) #=> [[1, "A"], [1, "B"], [2, "A"], [2, "B"]]
-  #
-  # or, if mixed in into Array,
-  #
-  #   [1,2].cartesian %w(A B) #=> [[1, "A"], [1, "B"], [2, "A"], [2, "B"]]
-  #
-  def Cartesian.product(first, second)
-    first.x(second).to_a
-  end
-
-  # Behaves as product, except for the elements are joined.
-  #
-  #   Cartesian::joined_cartesian( [1,2], %w(A B) ) #=> ["1A", "1B", "2A", "2B"]
-  #
-  # or, if mixed in into Array,
-  #
-  #   [1,2].joined_cartesian %w(A B) #=> ["1A", "1B", "2A", "2B"]
-  #
-  def Cartesian.joined_product(first, second)
-    product(first, second).map {|pair| pair.join }
-  end
-
-  # Cartesian.joined_product for mixin.
-  #
-  def joined_cartesian(other)
-    Cartesian.joined_product(self, other)
-  end
-
-  # Convenient way of iterating over the elements.
-  # Preferable when the cartesian product array
-  # is not needed, for the consumption of memory
-  # is fixed and very small, in contrast with the
-  # exponential memory requirements of the
-  # conventional approach.
-  #
-  #   for row, col in (1..10).x(1..30)
-  #     Matrix[row, col] = row**2 + col**3
-  #   end
-  #
-  # Of course, calls can be chained as in
-  #
-  #   for x, y, z in (1..10).x(1..10).x(1..10)
-  #     # ... do something ...
-  #   end
-  #
-  #--
-  #   for letter, number in %w{a b c}.x(1..3)
-  #     ... do something ...
-  #   end
-  #++
-  #
-  # Beware that both +self+ and +other+ must implement
-  # +to_a+, i.e., be convertible to array.
-  #
-  def x(other)
-    case other
-    when CartesianIterator
-      other.left_product(self)
-    else
-      CartesianIterator.new(self, other)
-    end
-  end
-  alias cartesian x
-  alias right_product x
-  
-  def left_product(other)
-    case other
-    when CartesianIterator
-      other.right_product(self)
-    else
-      CartesianIterator.new(other, self)
-    end
-  end
-
-  # Concise way of iterating multi-dimensionally
-  # over the same array or range.
-  #
-  # For instance,
-  #
-  #   for x,y,z in [0,1]**3
-  #     puts [x, y, z].join(',')
-  #   end
-  #
-  # produces the following output
-  #
-  #   0,0,0
-  #   0,0,1
-  #   0,1,0
-  #   0,1,1
-  #   1,0,0
-  #   1,0,1
-  #   1,1,0
-  #   1,1,1
-  #
-  # It also works with Range objects.
-  #
-  def **(fixnum)
-    if fixnum < 0
-      raise ArgumentError, "negative power"
-    elsif fixnum == 0
-      return []
-    elsif fixnum == 1
-      return self
-    else
-      iter = CartesianIterator.new(self, self)
-      (fixnum-2).times do
-        iter.product!(self)
-      end
-      iter
-    end
-  end
-  alias :power! :**
-end
-
-class Array
-  include Cartesian
-end
-
-class Range
-  include Cartesian
-end
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