#--
# $Id: tc_higher.rb 17 2006-09-17 18:03:15Z prelude $
#
#
#     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
#++

class TestHigher < Test::Unit::TestCase

  def setup
    # Nothing
  end # setup

  def teardown
    # Nothing
  end # teardown

  #
  # Test higher functions
  #
  def test_curry_proc
    add5 = (proc {|x,y,z| x+y+z}).curry(5)

    result = add5[3, 2]
    expect = 10

    assert_equal(expect, result)

    result = add5.call(3, 2)
    expect = 10

    assert_equal(expect, result)
  end

  def test_curry_symbol
    add5 = :+.curry(5)

    result = add5.call(3)
    expect = 8
    
    assert_equal(expect, result)

    result = add5[4]
    expect = 9
    
    assert_equal(expect, result)
  end

  def test_composition
    add5 = proc {|x| x+5}
    add6 = proc {|x,y| x+y+6}
    add11 = add5 ** add6

    result = add11[1, 2]
    expect = 14
    
    assert_equal(expect, result)

    result = add5 ** 1
    expect = 6
    
    assert_equal(expect, result)

    result = add5 ** add6 ** [1, 2]
    expect = 14
    
    assert_equal(expect, result)
  end

end # TestHigher