parameter.setToken(result);
// We have to validate the parameter so that
// value dependents (if any) are notified of
// the new value, and so that attributeChanged()
// is called on the actor.
parameter.validate();
} catch (IllegalActionException ex) {
ParseTreeFreeVariableCollector collector = new ParseTreeFreeVariableCollector();
Set expressionVariables = collector
.collectFreeVariables(parseTree);
Set scopeVariables = _scope.identifierSet();