Really Hitting the Wall on this LKit Feature
I'm trying to implement user-defined functions in LKit. and I'm having a really hard time with it. I'm not at all sure how to handle things with this addition - especially since I want to have recursion and pass-by-value work as you'd expect in a lisp-based language. The parsing of the code isn't the problem - that I've got figured out. But when I compile the code into an evaluation-tree, it's going to point to variables - some of which are defined outside the user-defined function, and some of them are the arguments to the function.
If they are the arguments, then we can't really have a static evaluation-tree… I'd have to have some kind of dynamic evaluation of the arguments for each invocation. It's getting to be a lot harder than I'd expected.
Now it's true that this was something that I didn't even attempt in my previous version of the code, but I was really hoping for something more this time. I'd even thought that I could bang out this function definition code today. Not so fast, it seems.
I need to handle the question of a calling stack. Really. I need to be able to "dive into" the evaluation of a function and then return to where I was. This is really a different layer than what I'm doing now, and it's going to take some significant time to think about it.
Well… maybe my next vacation.