class CommandParser
  def self.snippet(str)
    self.parse(self.lex(str))
  end
  def self.lex(str)
    tokens = []
    until str.nil? || str.empty?
      case str
      when /\A(?:\w|\.)+\(/
        tokens << [:fun_begin,$&]
      when /\A[\w.]+\s*<?=\s*/
        tokens << [:assignment,$&]
      when /\A[$\w.]+(?=,|)/
        tokens << [:term,$&]
      when /\A\.\.\./
        tokens << [:term,$&]
      when /\A,\s*/
        tokens << [:comma,$&]
      when /\A\)/
        tokens << [:fun_end,$&]
      when /\A".*?(?!\\)"/
        tokens << [:quoted,$&]
      when /\A\s*([\+\-\*\/!^]|&&|\|\|)\s*/
        tokens << [:operator,$&]
      when /\A\d+(\.\d+)?/
        tokens << [:number,$&]
      when /\A\{/
        tokens << [:brace_begin,$&]
      when /\A\}/
        tokens << [:brace_end,$&]
      when /\A\[/
        tokens << [:bracket_begin,$&]
      when /\A\]/
        tokens << [:bracket_end,$&]
      when /\A:/
        tokens << [:list_separator,$&]
      when /\s+/
      else
        pp str
        raise "Could not process: " + str
      end
      str = $'
    end
    tokens
  end
  def self.parse(data)
    str = ""
    snippet_counter = -1
    stack = [[:expression,""]]
    until data.empty?
      type,match = data.shift
      if !stack.empty? && stack.last[0] == :assignment && type.to_s =~ /comma|end$/ then
        temp_str = stack.pop[1]
        stack.last[1] += (temp_str + "}")
      end
      case type
      when :fun_begin, :brace_begin, :bracket_begin
        stack << [:group, ("${#{snippet_counter+=1}:#{match}${#{snippet_counter+=1}:")] << [:expression,""]
      when :assignment
        stack << [:assignment, "#{match}${#{snippet_counter+=1}:"]
      when :comma
        stack.last[1] += ("}${#{snippet_counter+=1}:" + match)
      when :brace_end, :bracket_end, :fun_end
        the_end = stack.pop[1] + ( "}#{match}}")
        the_whole = stack.pop[1] + the_end
        stack.last[1] += the_whole
      when :quoted
        stack.last[1] += "${#{snippet_counter+=1}:\"${#{snippet_counter+=1}:#{match[1..-2].gsub("}","\\}")}}\"}"
      else
        stack.last[1] += match
      end
    end
    raise "Too many levels" unless stack.length == 1
    stack[0][1][4..-2]
  end
end
require 'pp'
data=DATA.read.split("\n")
5.times do
  d = data[rand(2000)]
  pp [d, CommandParser.snippet(d)]
end