#--
#     This file is part of the Prelude library that provides tools to
#     enable Haskell style functional programming in Ruby.
#
#     http://prelude.rubyforge.org 
#     
#     Copyright (C) 2006 APP Design, Inc.
#
#     This library is free software; you can redistribute it and/or
#     modify it under the terms of the GNU Lesser General Public
#     License as published by the Free Software Foundation; either
#     version 2.1 of the License, or (at your option) any later version.
#
#     This library is distributed in the hope that it will be useful,
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
#     Lesser General Public License for more details.
#
#     You should have received a copy of the GNU Lesser General Public
#     License along with this library; if not, write to the Free Software
#     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
#++

module Prelude

  # $Id: monad.rb 7 2006-09-06 17:03:26Z prelude $
  #
  # The Monad is an Array only in an implementation sence of the word
  class Monad < Array

    def wrap(v)
      [v]
    end

    def empty
      []
    end
    
    def join
      r = []
      each {|a| r.push *a}
      r
    end

    def bind(&block)
      map(&block).join
    end

  end # Monad

end # Prelude