lex.cc

2007年机器人足球世界杯3D仿真组亚军

#include "parser.ih"

Parser::Token Parser::lex()
{
  Token tok;
  unsigned state;

  tok.type = Token::ws;
  tok.value = "";

  while (tok.type == Token::ws) {
    tok.value.clear();

    // If there is a token on the stack, return that one first.
    if (!lex_stack.empty()) {

      tok = lex_stack.top();
      lex_stack.pop();

    } else if (lex_iter == lex_source.end()) {
      // If we are at the end of the string, return end_of_line token.

      tok.type = Token::end_of_line;

    } else {

      lex_state = 1;

  while (true)
  {
	  state = lex_state;
      if (lex_iter != lex_source.end())
	      lex_state = lexerNextState(lex_state,*lex_iter);
      else
        lex_state = 0;
      
    if (!lex_state)
    {
      tok.type = isEndState(state);
	
	    if (tok.type)
	      break;
	    else
	    {
  	    //	throw lexer_error();
	      tok.type = Token::error;
	      break;
  	  }
	}
      
	tok.value += *(lex_iter)++;
      }
    }
  }  

  //  cerr << "Token(" << tok.type << ",'" << tok.value << "')." << endl;

  return tok;
}