1 files changed, 50 insertions, 2 deletions
diff --git a/src/core/script/Function.cpp b/src/core/script/Function.cpp
index d72df4c..ce6e6b6 100644
--- a/src/core/script/Function.cpp
+++ b/src/core/script/Function.cpp
@@ -21,9 +21,57 @@
 namespace ousia {
 namespace script {
 
-std::pair<bool, std::vector<Variant>> validate(const std::vector<Variant> &args)
+std::pair<bool, std::vector<Variant>> ArgumentValidator::setError(int idx,
+		const std::string &msg, std::vector<Variant> &res)
 {
-	return std::make_pair(true, std::vector<Variant>{});
+	errorIndex = idx;
+	errorMessage = msg;
+	return std::make_pair(false, res);
+}
+
+void ArgumentValidator::resetError()
+{
+	errorIndex = -1;
+	errorMessage = "";
+}
+
+std::pair<bool, std::vector<Variant>> ArgumentValidator::validate(
+		const std::vector<Variant> &args)
+{
+	std::vector<Variant> res;
+
+	// Reset any old error
+	resetError();
+
+	// Sanity check: Do not allow too many arguments
+	if (args.size() > descriptors.size()) {
+		return setError(descriptors.size(), "Expected " + std::to_string(descriptors.size()) +
+				" arguments but got " + std::to_string(args.size()), res);
+	}
+
+	// Iterate over the given arguments and check their type
+	res.reserve(descriptors.size());
+	for (unsigned int i = 0; i < args.size(); i++) {
+		// TODO: Implicit type conversion
+		const VariantType tGiven = args[i].getType();
+		const VariantType tExpected = descriptors[i].type;
+		if (tGiven != tExpected) {
+			return setError(i, std::string("Expected type ") + Variant::getTypeName(tExpected)
+				+ " but got " + Variant::getTypeName(tGiven), res);
+		}
+		res.push_back(args[i]);
+	}
+
+	// Make sure the remaining arguments have a default value, and if they have
+	// one, add it to the result
+	for (unsigned int i = args.size(); i < descriptors.size(); i++) {
+		if (!descriptors[i].hasDefault) {
+			return setError(i, "Expected argument " + std::to_string(i), res);
+		}
+		res.push_back(descriptors[i].defaultValue);
+	}
+
+	return std::make_pair(true, res);
 }
 
 }