hq9/hq9+

#!/usr/bin/env ruby
# HQ9++ is an object-oriented extension of the well-known esoteric language
# HQ9+, created by Cliff L. Biffle.
#
# From: http://www.dangermouse.net/esoteric/hq9plusplus.html
#
# Commands
#
# * H
#   Prints "Hello, world!".
# * Q
#   Prints the entire text of the source code file.
# * 9
#   Prints the complete canonical lyrics to "99 Bottles of Beer on the Wall".
# * +
#   Increments the accumulator.
# * ++
#   When the sequence ++ is encountered, it (naturally) increments the
#   accumulator twice, and also instantiates an object of a new subclass of the
#   generic superclass. In line with the best data-hiding principles, there is
#   no way to access this object. 

plusplus = true
source = gets

def beer(n)
  if n == 1 
    puts "1 bottle of beer on the wall"
    puts "1 bottle of beer"
    puts "Take one down and pass it around"
    puts "No bottles of beer on the wall"
  else 
    puts "#{n} bottles of beer on the wall"
    puts "#{n} bottles of beer"
    puts "Take one down and pass it around"
    puts "#{n-1} bottles of beer on the wall"
    puts
    beer(n-1)
  end
end

accumulator = 0
last_instruction = nil
objects = []

source.split(//).each do |instruction|
  case instruction 
  when "H"
    puts "Hello world!"
  when "Q"
    puts source
  when "9"
    beer(99)
  when "+"
    accumulator += 1
    if plusplus && last_instruction == "+"
      objects << Class.new.new
    end
  when "\n", " " 
  else
    die "Syntax error"
  end 
  last_instruction = instruction
end