Esempio n. 1
0
        /// <summary>
        /// Binds this function to an instance of a class,
        /// allowing it to access the instance's 'this' variable.
        /// </summary>
        /// <param name="instance">Instance to bind to.</param>
        /// <returns>The bound function.</returns>
        public Function Bind(Instance instance)
        {
            var environment = new EnvironmentState(outerEnvironment: _closure);

            environment.Define("this", instance);
            return(new Function(_declaration, environment, _name, _isInit));
        }
Esempio n. 2
0
        /// <summary>
        /// Calls the function.
        /// </summary>
        /// <param name="interpreter">Interpreter calling the function.</param>
        /// <param name="arguments">Arguments to pass to the function.</param>
        /// <returns>The result of the function call.</returns>
        public object Call(Interpreter interpreter, IEnumerable <object> arguments)
        {
            // each call gets its own scope so that it can keep track of its individual state
            var environment = new EnvironmentState(outerEnvironment: _closure);

            // combine the params and the arguments into one collection
            var paramArguments = _declaration.Params.Zip(arguments, (param, argument) => new
            {
                Name  = param.WrappedSource,
                Value = argument
            });

            // define scoped variables for each param/argument
            foreach (var item in paramArguments)
            {
                environment.Define(item.Name, item.Value);
            }

            try
            {
                // execute the function body with the new scope we just created
                interpreter.ExecuteBlock(_declaration.Body, environment);
            }
            catch (ReturnException ex)
            {
                return(_isInit
                    ? _closure.GetValue("this", 0)
                    : ex.Value);
            }

            // constructors will always return 'this'
            return(_isInit
                ? _closure.GetValue("this", 0)
                : null);
        }