oop_test.rb

require 'open-uri'
WORD_URL="http://learncodethehardway.org/words.txt"
WORDS=[]
PHRASES={
  "class ### < ###\n end"=>
        "Make a class named ### that is-a ###. ",
  "class ###\n\tdef initialize(@@@)\n\tend\nend"=>
        "class ### has-a initialize that take @@@ parameters.",
  "class ###\n\tdef ***(@@@)\n\tend\nend" =>
       "class ### has-a function named *** that takes @@@ parameters.",
  "*** = ###.new()" =>
       "Set *** to an instance of class ###.",
  "***.***(@@@)" =>
       "From *** get the *** function, and call it with parameters @@@.",
  "***.*** = '***'" =>
       "From *** get the *** attribute and set it to '***'."
}

PHRASE_FIRST=ARGV[0]=="english"
open(WORD_URL){|f|
  f.each_line{|word| WORDS.push(word.chomp)}
}

def craft_names(rand_words,snippet,pattern,caps=false)
  names=snippet.scan(pattern).map do 
    word=rand_words.pop()
    caps ? word.capitalize : word
  end

  return names * 2
end
def craft_params(rand_words,snippet,pattern)
  names=(0...snippet.scan(pattern).length).map do
    param_count=rand(3)+1
    params=(0...param_count).map{|x| rand_words.pop() }
    params.join(', ')
  end

  return names*2
end

def convert(snippet,phrase)
  rand_words=WORDS.sort_by{rand}
  class_names=craft_names(rand_words,snippet,/###/,caps=true)
  other_names=craft_names(rand_words,snippet,/\*\*\*/)
  param_names=craft_params(rand_words,snippet,/@@@/)

  results=[]
  [snippet, phrase].each do |sentence|
    #fake class names,also copies sentence
    result=sentence.gsub(/###/){|x| class_names.pop}
    #fake other names
    result.gsub!(/\*\*\*/){|x| other_names.pop}
    #fake parameter lists
    result.gsub!(/@@@/){|x| param_names.pop}
    results.push(result)
  end

  return results
end

#keep going until they hit CTRL-D
loop do
 snippets=PHRASES.keys().sort_by {rand}
 for snippet in snippets
  phrase=PHRASES[snippet]
  question, answer=convert(snippet,phrase) 
  if PHRASE_FIRST
    question,answer = answer,question
  end
  print question,"\n\n>"
  exit(0) unless $stdin.gets
  puts "\nAnswer: %s\n\n" % answer
 end
end