/** @see org.vedantatree.expressionoasis.expressions.UnaryOperatorExpression#validate() */
@Override
protected void validate(ExpressionContext expressionContext) throws ExpressionEngineException {
// Initializes the function provider.
ParanthesisExpression argsExpression = (ParanthesisExpression) getOperandExpression();
List<Type> types = new ArrayList<Type>();
List values = new ArrayList();
populateTypesAndValues(argsExpression.getOperandExpression(), types, values);
Type[] parameterTypes = (Type[]) types.toArray(new Type[types.size()]);
for (Iterator functionProviders = expressionContext.getFunctionProviders().iterator();
functionProviders.hasNext(); ) {
FunctionProvider functionProvider = (FunctionProvider) functionProviders.next();
if (functionProvider.supportsFunction(functionName, parameterTypes)) {
this.functionProvider = functionProvider;
break;
}
}
if (functionProvider == null) {
throw new ExpressionEngineException(
"No Function Provider exists for function: ["
+ MethodKey.generateKey(functionName, parameterTypes)
+ "]");
}
}
/** @see org.vedantatree.expressionoasis.expressions.Expression#getValue(java.lang.Object) */
public ValueObject getValue() throws ExpressionEngineException {
List<ValueObject> values = new ArrayList<ValueObject>();
ParanthesisExpression argsExpression = (ParanthesisExpression) getOperandExpression();
populateTypesAndValues(argsExpression.getOperandExpression(), null, values);
ValueObject[] parameters = (ValueObject[]) values.toArray(new ValueObject[values.size()]);
return functionProvider.getFunctionValue(functionName, parameters);
}
/** @see org.vedantatree.expressionoasis.expressions.Expression#getReturnType() */
@Override
public Type getReturnType() throws ExpressionEngineException {
List<Type> types = new ArrayList<Type>();
ParanthesisExpression argsExpression = (ParanthesisExpression) getOperandExpression();
populateTypesAndValues(argsExpression.getOperandExpression(), types, null);
Type[] parameterTypes = (Type[]) types.toArray(new Type[types.size()]);
return functionProvider.getFunctionType(functionName, parameterTypes);
}