/**
* Checks a binary predicate for a type matching the type parameters.
*
* @param pred a predicate to check.
* @param type1 the proposed type of parameter 1.
* @param type2 the proposed type of parameter 2.
* @return true if <code>pred</code> is a binary predicate that matches the types.
*/
protected static String checkTypes(
Predicate pred, Predicate.ParamType type1, Predicate.ParamType type2) {
if (pred.getArity() != 2) return formatError(pred, "expected 2 arguments");
else if (pred.getParamType(0) != type1)
return formatError(pred, "argument 1 should be type " + type1);
else if (pred.getParamType(1) != type2)
return formatError(pred, "argument 2 should be type " + type2);
return null;
}
/**
* Attempts to evalutate or assert the predicate by searching for and executing a method named
* "a_[PredicateName]" (where [PredicateName] is the name of the Predicate object <code>pred
* </code>) and that has a parameter type list that matches the predicate's parameter type list.
*
* @param isAssert true if this is to be interpreted as an assertion, false if it's to be treated
* as an evaluation.
* @param pred a predicate object to assert or evaluate.
* @return the value returned by the method described above; false if something when wrong.
*/
private boolean assert_or_eval(boolean isAssert, Predicate pred) {
currentPred = pred;
String predName = pred.getName();
if (predName == null || predName.length() == 0) return false;
String methodName = (isAssert ? "a_" : "e_") + predName.replaceAll("-", "_");
int arity = pred.getArity();
Class<?>[] paramTypes = new Class[arity];
Object[] paramValues = new Object[arity];
for (int i = 0; i < arity; i++) {
switch ((Predicate.ParamType) pred.getParamType(i)) {
case STRING:
paramTypes[i] = String.class;
paramValues[i] = pred.getStringParam(i);
break;
case SET:
paramTypes[i] = TreeSet.class;
paramValues[i] = pred.getSetParam(i);
break;
case LONG:
paramTypes[i] = Long.class;
paramValues[i] = pred.getLongParam(i);
break;
default:
error(
(isAssert ? "!" : "")
+ pred.toString()
+ ": Unrecognized argument type argument "
+ i
+ " in Predicate");
return false;
}
}
try {
Method m = this.getClass().getMethod(methodName, paramTypes);
Object ret = m.invoke(this, paramValues);
if (ret instanceof Boolean) return ((Boolean) ret).booleanValue();
} catch (InvocationTargetException e) {
error(
formatLineNumber()
+ (isAssert ? "!" : "")
+ pred.toString()
+ ": InvocationTargetException ("
+ e.getCause()
+ ")");
e.getTargetException().printStackTrace();
} catch (Exception e) {
error(
formatLineNumber()
+ (isAssert ? "!" : "")
+ pred.toString()
+ ": predicate not found or failed ("
+ e.toString()
+ ")");
}
return false;
}