protected static Symbol real_next_token()

in util/src/main/java/java_cup/lexer.java [469:564]

• 68 lines of code
• 23 McCabe index (conditional complexity)

  protected static Symbol real_next_token() throws java.io.IOException
    {
      int sym_num;

      for (;;)
	{
	  /* look for white space */
	  if (next_char == ' ' || next_char == '\t' || next_char == '\n' ||
	      next_char == '\f' ||  next_char == '\r')
	    {
	      /* advance past it and try the next character */
	      advance();
	      continue;
	    }

	  /* look for a single character symbol */
	  sym_num = find_single_char(next_char);
	  if (sym_num != -1)
	    {
	      /* found one -- advance past it and return a Symbol for it */
	      advance();
	      return new Symbol(sym_num);
	    }

	  /* look for : or ::= */
	  if (next_char == ':')
	    {
	      /* if we don't have a second ':' return COLON */
	      if (next_char2 != ':') 
		{
		  advance();
		  return new Symbol(sym.COLON);
		}

	      /* move forward and look for the '=' */
	      advance();
	      if (next_char2 == '=') 
		{
		  advance(); advance();
		  return new Symbol(sym.COLON_COLON_EQUALS);
		}
	      else
		{
		  /* return just the colon (already consumed) */
		  return new Symbol(sym.COLON);
		}
	    }

	  /* find a "%prec" string and return it.  otherwise, a '%' was found,
	     which has no right being in the specification otherwise */
	  if (next_char == '%') {
	    advance();
	    if ((next_char == 'p') && (next_char2 == 'r') && (next_char3 == 'e') && 
		(next_char4 == 'c')) {
	      advance();
	      advance();
	      advance();
	      advance();
	      return new Symbol(sym.PERCENT_PREC);
	    } else {
	      emit_error("Found extraneous percent sign");
	    }
	  }

	  /* look for a comment */
	  if (next_char == '/' && (next_char2 == '*' || next_char2 == '/'))
	    {
	      /* swallow then continue the scan */
	      swallow_comment();
	      continue;
	    }

	  /* look for start of code string */
	  if (next_char == '{')
          if (next_char2 == ':')
	          return do_code_string();
          else {
              advance ();
              return new Symbol(sym.LBRACE);
          }

	  /* look for an id or keyword */
	  if (id_start_char(next_char)) return do_id();

	  /* look for EOF */
	  if (next_char == EOF_CHAR) return new Symbol(sym.EOF);

	  /* if we get here, we have an unrecognized character */
	  emit_warn("Unrecognized character '" + 
	    new Character((char)next_char) + "'(" + next_char + 
	    ") -- ignored");

	  /* advance past it */
	  advance();
	}
    }