Contents

class ImmutableQueue
      def push(element) b = (back or ImmutableStack.empty)
ImmutableQueue.new(front, b.push(element))
 end
 def pop() f, b = front, back
if (f == ImmutableStack.empty) then
  until (b == ImmutableStack.empty) do
    (e, b = b.pop
    f = f.push(e))
  end
end
head, f = f.pop
if (f == b) then
  [head, ImmutableQueue.empty]
else
  [head, ImmutableQueue.new(f, b)]
end
 end
 def self.empty() @empty ||= ImmutableQueue.new(ImmutableStack.empty, ImmutableStack.empty) end
 def push_array(arr) q = self
arr.each { |i| q = q.push(i) } if arr
q
 end
     private
def initialize(front,back) @front = (front or ImmutableStack.empty)
@back = (back or ImmutableStack.empty)
self.freeze
 end

attr_reader :front, :back

           end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
maroon-0.8.0	lib/ImmutableQueue.rb