Re: [stack] Constant folding algorithm

Daniel Ehrenberg <[email protected]> wrote:
> Right now, I'm working on a module called inverse for Factor. The
> basic goal is to provide an inverse (or, technically, a section) of a
> quotation, for a generalized form of pattern matching. I've noticed

Wow, that's impressive.

> that this can work both more efficiently and more generally if I first
> perform constant folding on the quotation, for example transforming [
> 1 2 + * ] into [ 3 * ], which can more easily be inverted. Right now,

That makes sense. A friend of mine has an algorithm for Forth which
seems to catch a lot of opportunities for optimization (including
stack manipulation and constant folding); I'll see if I can convince
him to either write it up or join this list. In essence, he uses a
stack at compile time to track the type and knownness of values
encountered and/or produced. It's linear time, so it's not hard to
understand.

> looks like one area where it's a little easier to manipulate an
> applicative programming language than a concatenative one, though I'm

Heh. I doubt it.

> Daniel Ehrenberg

-Wm