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()) ;
}
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;
}
}