More Functional Fun In Ruby

I have no clue whenever this will be useful, but it was a fun exercise. Hope you enjoy it as well. It's an implementation of Lisp's cons, car, and cdr.

def pair(left,right)
  lambda do |dyadic|
    dyadic.call(left,right)
  end
end

def left(pair)
  pair.call(lambda {|left,right| left})
end

def right(pair)
  pair.call(lambda {|left,right| right})
end

require 'rubyunit'

class WorkspaceTest < Test::Unit::TestCase
  def test_simple
    a_b=pair('a','b')
    assert_equal('a',left(a_b))
    assert_equal('b',right(a_b))
  end
  
  def test_again
    a_b=pair('a', 'b')
    c_a_b=pair('c', a_b)
    assert_equal('c', left(c_a_b))
    assert_equal('a', left(right(c_a_b)))
  end
end