Example #1
0
  public void parse(Lexico scanner, Semantico semanticAnalyser)
      throws LexicalError, SyntaticError, SemanticError {
    this.scanner = scanner;
    this.semanticAnalyser = semanticAnalyser;

    stack.clear();
    stack.push(new Integer(DOLLAR));
    stack.push(new Integer(START_SYMBOL));

    currentToken = scanner.nextToken();

    while (!step()) ;
  }
Example #2
0
  private boolean step() throws LexicalError, SyntaticError, SemanticError {
    if (currentToken == null) {
      int pos = 0;
      if (previousToken != null)
        pos = previousToken.getPosition() + previousToken.getLexeme().length();

      currentToken = new Token(DOLLAR, "$", pos);
    }

    int x = ((Integer) stack.pop()).intValue();
    int a = currentToken.getId();

    if (x == EPSILON) {
      return false;
    } else if (isTerminal(x)) {
      if (x == a) {
        if (stack.empty()) return true;
        else {
          previousToken = currentToken;
          currentToken = scanner.nextToken();
          return false;
        }
      } else {
        throw new SyntaticError(PARSER_ERROR[x], currentToken.getPosition());
      }
    } else if (isNonTerminal(x)) {
      if (pushProduction(x, a)) return false;
      else throw new SyntaticError(PARSER_ERROR[x], currentToken.getPosition());
    } else // isSemanticAction(x)
    {
      if (executaAcoesSemanticas) {
        semanticAnalyser.executeAction(x - FIRST_SEMANTIC_ACTION, previousToken);
      }
      return false;
    }
  }