gistfile1.rb

# Ruby implementation of Smalltalk's "if" construction. See also
# http://pozorvlak.livejournal.com/94558.html
#
# Note that since I can't cleanly pass in more than one anonymous block to a
# method in Ruby, I have to implement it as two methods rather than
# Smalltalk's cleaner "ifTrue:ifElse:" single method. This means that in order
# to get the syntax for chaining, I lose Ruby's ability to return a value from
# "if", which is pretty cool in itself.
#
class TrueClass
  def ifTrue
    yield
    self
  end
  def ifFalse
    self
  end
end

class FalseClass
  def ifTrue
    self
  end
  def ifFalse
    yield
    self
  end
end

[1,2,3,4].each do |x|
  (x % 2 == 0).
    ifTrue {puts "#{x} is even"}.
    ifFalse {puts "#{x} is odd"}
end