Ejemplo n.º 1
0
        /// <summary>
        /// Changes the execution context to the current environment's parent, and then jumps to the 
        /// address on the ReturnAddress stack. In other words, this explicitly closes dynamic scope.
        /// </summary>
        /// <param name="vm"></param>
        /// <param name="i"></param>
        internal static void Return(VirtualMachine vm, Instruction i)
        {
            if (vm.CurrentEnvironment.Parent == null) {
                // We're at the top of the chain, so end execution.
                vm.RaiseError("Attempted to return without any parent environment.");
                return;
            }
            if (vm.Stack.Count() > 0) {
                Value val = vm.Stack.Shift();
                vm.CurrentEnvironment.Parent.Stack.Push(val);
            }
            vm.PopCurrentEnvironment();
            vm.ByteCode.ProgramCounter = vm.ReturnAddresses[vm.ReturnAddresses.Count() - 1];

            // Pop off this return address
            vm.ReturnAddresses.RemoveAt(vm.ReturnAddresses.Count() - 1);

            // Pop off the CodeBlock saved for this function
            vm.FunctionCallList.RemoveAt(vm.FunctionCallList.Count() - 1);
        }