truecolor.rb

#!/usr/bin/env ruby

# Usage example: sml hw1test.sml | truecolor.rb

require 'colorize'

true_pat = /\btrue\b/
false_pat = /\bfalse\b/

true_count = 0
false_count = 0

while line = gets
  puts line.gsub(true_pat) { true_count += 1; 'true'.green }
           .gsub(false_pat) { false_count += 1; 'false'.red }
end

puts true_count.to_s.green + ' passed' +
  if false_count > 0
    ', ' + false_count.to_s.red + ' failed'
  else
    ''
  end