Hmm, I kinda prefer local variables over common subexpressions. It's apparently not for refactoring's sake, since I just name the variables after the way they're calculated, so it must just be a premature optimization thing. :-p
But yeah, that particular example has a few ways it can be improved. Here's what I'm thinking:
(=fn my.deglobalize-var (var)
(zap expand var)
(or (when anormalsym.var var)
(errsafe:let (global (quot inner-var . qs) . gs) var
(and (is global 'global)
(is quot 'quote)
no.qs
no.gs
anormalsym.inner-var
inner-var))
(err:+ "An unrecognized kind of name was passed to "
"'deglobalize-var.")))
I still like 'scope, but I'm fresh out of significant uses for it.
(To continue the digression into this particular case...) I had thought about destructuring, but found the need for qs and gs ugly. Really, a pattern matching library would be opportune. But since there's no such luck in Arc proper, it'd be ad-hoc and probably altogether not worth it (though not difficult to implement). I say this with respect to vanilla Arc; I don't know if Anarki has such a library. Still, it'd be hard to beat something like
(=fn my.deglobalize-var (var)
(zap expand var)
(or (check var anormalsym)
(when-match (global (quote ?inner-var)) var
(check ?inner-var anormalsym))
(err "An unrecognized kind of name was passed to 'deglobalize-var.")))
