[racket-dev] Adding flvector to match

From: Neil Toronto (neil.toronto at gmail.com)
Date: Thu Apr 17 18:48:25 EDT 2014

It would be really handy for me right now to be able to match on 
flvectors, and I think it's useful enough for minimal Racket. I've 
already tried this option:

  1. Export flvector as a match expander from racket/flonum

but racket/match depends on racket/flonum somehow. So I looked through 
the match code and determined that this one would be pretty easy:

  2. Change racket/match to recognize patterns with 'flvector head

(The code is very clean; kudos to whoever last rewrote it. :D)

I think #2 would at worst hijack someone's custom flvector match 
expander, but probably do the same thing or better (e.g. also handle 
ellipses). But in case it's worse than I think, I can always go with this:

  3. Export flvector as a match expander from math/flonum

Question for the match and syntax gurus: would doing #2 be safe enough, 
or should I do #3? Or have I got it backwards; i.e. is #2 actually safer 
than #3?

Neil ⊥

Posted on the dev mailing list.