[Feat Request] Exhaustive pattern-matching for `defn` about carp

[hellerve]

You might be interested in a library I’ve written, match-utils which, among other things, supports this kind of function definition.

[AZMCode]

That is indeed quite useful.
Should this sort of functionality then be provided via library instead of through the language?

[hellerve]

It depends. I did it because I felt like it was a fun challenge, and honestly because programming in Carp is more fun to me than programming in Haskell.

It does have the limitation of introducing another form, though, because you can’t really override defn—well, I suppose you could, but I wasn’t quite daring enough.

We’ve had some conversations about what should be a macro and what shouldn’t be in the past. I’m a bit of a macro maximalist, so my view is skewed. The proper objective limitation is that macros are somewhat slow; match-utils actually has an optimization pass under the hood that reorders matches to limit how many branches are needed.[1] That optimization pass runs in macro world, and macro world is not exactly blazingly fast (it’s a tree-walking interpreter, essentially). In my opinion we should just bite the bullet and optimize it, but I don’t think anyone has the time or energy to do that at the moment.

[1] I’ve got a fun paper on that lying around if you’re really interested.

[AZMCode]

Huh. I may not be at that level yet.
Perhaps there should be a protocol to determine what ultimately gets done with the language?
Are you the BDFL of this language?

[AZMCode]

Anyways, that's not a topic for this issue. Closing.