#!/usr/bin/ruby

=begin
S式のパーサ
=end

class SParser
  def SParser.parse(istream)
    parserd = []
    last_by_level = [parsed]
    
    current = []
    on_string = false
    on_ignore = true
    while !istream.eof?
      c = istream.read(1)
      if on_string then
        if c == '\\' then
          if c = istream.read(1) then
            current << c
          end
        elsif c == '"' then
          on_string = false
        else
          current << c
        end
      else
        case c
        when '\\':
          if c = istream.read(1) then
            current << c
          end
        when '(':
          if current && !current.empty? then
            last_by_level.last << current.join
            current = []
          end
          next_level = []
          last_by_level.last << next_level
          last_by_level << next_level
        when ')':
          if current && !current.empty? then
            last_by_level.last << current.join
            current = []
          end
          last_by_level.pop
        when '"':
          on_string = true
        when /\s/:
          if current && !current.empty? then
            last_by_level.last << current.join
            current = []
          end
        else
          current << c
        end
      end
    end
    
    if last_by_level.size != 1 then
      raise Exception::new("incorrect EDIF!!")
    end
    
    return parsed
  end
end


if $0 == __FILE__ then
  open(ARGV.shift){|io|
    p SParser.parse(io)
  }  
end