Yes, ~f means the same as no:f. So far I like the brief and distinctive look of negated functions thus: ~foo. But since potential symbol-syntax chars are rare, I might use ~ for something else one day if negated fns turn out not to be too common. There are currently only 9 in news.arc (1410 LOC).
Edit: Looks like there could be 4 more. Most of news.arc was written before ssyntax, so it's not maximally up to date.
complement only works with functions. behind the scenes, it uses apply to call the original function. at first glance, i don't really see a reason that it couldn't just do the same as (compose no _)
I know compose works on macros... but I'm not sure you are straight on, because compose uses apply as well. And the macro expansions look exactly the same.
arc> (macex '(compose no litmatch))
(fn gs1639 (no (apply litmatch gs1639)))
arc> (macex '(complement litmatch))
(fn gs1641 (no (apply litmatch gs1641)))
arc> ((compose no litmatch) "a" "aston")
nil
arc> ((complement litmatch) "a" "aston")
Error: "vector-ref: expects type <non-negative exact integer> as 2nd argument,
given: \"a\"; other arguments were: #3(tagged mac #<procedure>)"
except calls to compose are optimized away in the interpreter. they are treated specially. look in the `ac' function in ac.scm. i'm guessing this is the reason.
Now, what to do about the other case... there's still no reason it should bug out, it seems to me. Or rather, it should be implementable in such a way that it shouldn't.
Yes, we do. But if I recall (and I can't test, because the git "wiki" broke for later mzschemes again), apply does work for macros, except it evaluates all the arguments first, which breaks things like and. Someone should test that, though; as I noted, I can't.
I saw, that's how I was able to test. Thank you for setting it up, by the way! And if you fixed it, thank you for that; if someone else did, thank them for that.
