From 4a9912f516bf096c6f8c6259b3fc6ba4b95b8d69 Mon Sep 17 00:00:00 2001
From: Andreas Stöckel <astoecke@techfak.uni-bielefeld.de>
Date: Fri, 24 Oct 2014 13:25:04 +0000
Subject: finished implementation of HostFunction

git-svn-id: file:///var/local/svn/basicwriter@74 daaaf23c-2e50-4459-9457-1e69db5a47bf
---
 src/core/script/Function.hpp | 67 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 66 insertions(+), 1 deletion(-)

(limited to 'src/core/script/Function.hpp')

diff --git a/src/core/script/Function.hpp b/src/core/script/Function.hpp
index 35e2205..4c13dbc 100644
--- a/src/core/script/Function.hpp
+++ b/src/core/script/Function.hpp
@@ -46,6 +46,13 @@ public:
 	 */
 	virtual Variant call(const std::vector<Variant> &args) const = 0;
 
+	/**
+	 * Calls the underlying function with no arguments.
+	 *
+	 * @return a Variant containing the return value.
+	 */
+	Variant call() const { return call({}); }
+
 };
 
 /**
@@ -70,7 +77,7 @@ struct ArgumentDescriptor {
  * ArgumentValidatorError is an exception type used to represent argument
  * validator errors.
  */
-class ArgumentValidatorError : std::exception {
+class ArgumentValidatorError : public std::exception {
 
 public:
 
@@ -110,6 +117,11 @@ private:
 	 */
 	std::string errorMessage;
 
+	std::pair<bool, std::vector<Variant>> setError(int idx,
+			const std::string &msg, std::vector<Variant> &res);
+
+	void resetError();
+
 public:
 
 	/**
@@ -153,6 +165,59 @@ public:
 /**
  * The HostFunction class represents a function that resides in the script host.
  */
+template<class T>
+class HostFunction : public Function {
+
+private:
+	T callback;
+	ArgumentValidator *validator;
+	void *data;
+
+public:
+
+	HostFunction(T callback, std::vector<ArgumentDescriptor> signature,
+			void *data = nullptr) :
+		callback(callback), validator(new ArgumentValidator(signature)),
+		data(data) {}
+
+	HostFunction(T callback, void *data = nullptr) :
+		callback(callback), validator(nullptr), data(data) {}
+
+	~HostFunction()
+	{
+		delete validator;
+	}
+
+	virtual Variant call(const std::vector<Variant> &args) const override
+	{
+		if (validator) {
+			std::pair<bool, std::vector<Variant>> res = validator->validate(args);
+			if (!res.first) {
+				throw validator->error();
+			}
+			return callback(res.second, data);
+		} else {
+			return callback(args, data);
+		}
+	}
+
+	using Function::call;
+
+};
+
+template<class T>
+static HostFunction<T> createHostFunction(T callback,
+		std::vector<ArgumentDescriptor> signature, void *data = nullptr)
+{
+	return HostFunction<T>(callback, signature, data);
+}
+
+template<class T>
+static HostFunction<T> createHostFunction(T callback, void *data = nullptr)
+{
+	return HostFunction<T>(callback, data);
+}
+
 
 }
 }
-- 
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