From: Johnny Morrice <spoon@...>
Date: 2011-05-06T21:04:02+09:00
Subject: Re: Lets play a guessing game. (how to code this better?)

Actually I left a bug in that due to side effects.  (When will lazy
functional ruby be out?)

Here you go:

# I have defined the combinators as constants to reflect the TRUTH and
PURITY of COMPUTER SCIENCE

# Z combinator defines explicit recursion
Z = lambda { |f| (lambda {|x| f.call(lambda {|*ys|
x.call(x).call(*ys)})}).call(lambda {|x| f.call(lambda {|*ys|
x.call(x).call(*ys)})})}

# The guess combinator holds a reference to itself in the 'again'
variable Guess = lambda do |again|
	lambda do |magic|
		print "Choose 0-100> "
		n = gets.to_i
		if (0..100).include?(n)
			puts "Higher!" if n<magic
			puts "Lower!" if n>magic
			if n==magic
				puts "You won: #{magic} is the number!"
			else
				again.call magic
			end
		else
			puts "0-100!" 
			again.call magic
		end
	end
end

magic = rand(101).to_i
puts "Guess the magic number!"

Z.call(Guess).call(magic)