@Override
public SemanticContext evalPrecedence(Recognizer<?, ?> parser, RuleContext parserCallStack) {
boolean differs = false;
List<SemanticContext> operands = new ArrayList<SemanticContext>();
for (SemanticContext context : opnds) {
SemanticContext evaluated = context.evalPrecedence(parser, parserCallStack);
differs |= (evaluated != context);
if (evaluated == NONE) {
// The OR context is true if any element is true
return NONE;
} else if (evaluated != null) {
// Reduce the result by skipping false elements
operands.add(evaluated);
}
}
if (!differs) {
return this;
}
if (operands.isEmpty()) {
// all elements were false, so the OR context is false
return null;
}
SemanticContext result = operands.get(0);
for (int i = 1; i < operands.size(); i++) {
result = SemanticContext.or(result, operands.get(i));
}
return result;
}
/**
* {@inheritDoc}
*
* <p>The evaluation of predicates by this context is short-circuiting, but unordered.
*/
@Override
public boolean eval(Recognizer<?, ?> parser, RuleContext parserCallStack) {
for (SemanticContext opnd : opnds) {
if (opnd.eval(parser, parserCallStack)) return true;
}
return false;
}
/**
* Given an arbitrarily complex SemanticContext, walk the "tree" and get display string. Pull
* predicates from grammar text.
*/
public String getSemanticContextDisplayString(SemanticContext semctx) {
if (semctx instanceof SemanticContext.Predicate) {
return getPredicateDisplayString((SemanticContext.Predicate) semctx);
}
if (semctx instanceof SemanticContext.AND) {
SemanticContext.AND and = (SemanticContext.AND) semctx;
return joinPredicateOperands(and, " and ");
}
if (semctx instanceof SemanticContext.OR) {
SemanticContext.OR or = (SemanticContext.OR) semctx;
return joinPredicateOperands(or, " or ");
}
return semctx.toString();
}