/// <summary>
/// This is similar to the way we handle closures, except functions don't have durable
/// state, so we destroy the environment after using.
/// </summary>
/// <param name="vm"></param>
/// <param name="i"></param>
internal static void ReturnFunction(VirtualMachine vm, Instruction i)
{
if (vm.ClosureStack.Count() < 1) {
vm.RaiseError("Attempted to return a function without any outer context.");
return;
}
Environment temporaryEnv = vm.CurrentEnvironment;
Environment enviro = vm.ClosureStack.Last();
vm.ClosureStack.RemoveAt(vm.ClosureStack.Count() - 1);
if (vm.Stack.Count() > 0) {
Value val = vm.Stack.Shift();
enviro.Stack.Push(val);
}
vm.CurrentEnvironment = enviro;
vm.ByteCode.ProgramCounter = vm.ReturnAddresses[vm.ReturnAddresses.Count() - 1];
vm.ReturnAddresses.RemoveAt(vm.ReturnAddresses.Count() - 1);
vm.FunctionCallList.RemoveAt(vm.FunctionCallList.Count() - 1);
vm.DestroyClosure(temporaryEnv);
return;
}
