On Jul 15, 2014, at 5:40 PM, Stephen Chang <stch...@ccs.neu.edu> wrote:
>> Is there any reason why you can’t just use match-patterns instead of using >> ($ match-pattern) ? > > The idea was to support a generic interface so different instances > could be defined, but thus each instance needs it's own name. For > example, I need to differentiate when I'm binding a match pattern vs > binding multiple values. > > I tried to define shortcuts for some match patterns like $list and I > suppose you could rename them to be the same as racket but I didnt > want to clash with racket's names. There's also define-match-bind to > create your own shortcuts. Ok that makes sense. > > >> And is there anything like a “generic-binding-expander” that would act sort >> of like a match-expander? > > No there isnt. It was a todo but I never got around to it. Did you > have something specific in mind? No, I just thought that it would be really useful and wanted to know if it was there. Also I was thinking I could use it to make gen-bind expanders for match-patterns if I need them. > > >> And is there some kind of "generic-bind/renamed” module or something that >> provides everything from generic-bind except without the ~ in front? > > Good idea. Yes, in hindsight my choice of names was probably > suboptimal. I've incorporated your suggestion so now you can do > (require generic-bind/as-rkt-names), which drops all ~-prefixes > (except for ~vs). Thanks! > > >> >> >> On Jul 15, 2014, at 3:02 PM, Stephen Chang <stch...@ccs.neu.edu> wrote: >> >>>> I just found this, which has a lot of forms for just about everything I >>>> can think of (and more) that support things like match-patterns: >>>> https://github.com/stchang/generic-bind >>>> >>>> I haven’t tried it yet, but It looks pretty amazing. >>>> >>>> It probably has everything you want. >>> >>> Thanks for the kind words. :) >>> >>> This was an experiment that tried to address a few questions that >>> repeatedly get asked on the mailing list: >>> >>> 1) that you can't destructure data structures at the binding site, and >>> 2) that you need to manually define many different versions of each >>> binding construct (eg define, match-define, match-define-values, etc), >>> which inevitably means that some binding forms don't exist (eg >>> match-for/X forms) >>> >>> Something like the expressivity problem for binding forms. >>> >>> I tried to implement one "generic" version of each binding form that >>> would accept many different "binding instances", so every binding form >>> would be extensible by implementing the appropriate instance (eg, a >>> matching instance, a values instance) >>> >>> Every Racket binding form should have a ~-prefixed version in my >>> library and my version should work as a drop-in replacement for its >>> Racket counterpart if you want to try it out. >>> >>> Here's a link to the docs if you're interested in reading more: >>> http://stchang.github.io/generic-bind/generic-bind.html >>> >>> (You can tell that it hasn't been updated in a while from the old css.) >>> >>> Caveat: my macro-fu hasn't quite reached expert level so I'd love for >>> anyone to tell me where my code is bad. >>> >>> That being said, I ran a large part of the Racket test suite using my >>> binding forms instead of the Racket ones so they should be usable in >>> most scenarios. >>> >>> >>> >>> >>> >>> >>> >>>> >>>> On Jul 13, 2014, at 12:41 AM, Alexander D. Knauth <alexan...@knauth.org> >>>> wrote: >>>> >>>>> >>>>> On Jul 12, 2014, at 10:17 PM, Alexander D. Knauth <alexan...@knauth.org> >>>>> wrote: >>>>> >>>>>> >>>>>> On Jul 12, 2014, at 6:43 PM, Brian Adkins <racketus...@lojic.com> wrote: >>>>>> >>>>>>> I probably won't keep my defpat macro, at least not in its present form >>>>>>> (for one, it only handles a single arg); there's probably a balance >>>>>>> between being concise and being general/flexible. >>>>>> >>>>>> Although define/match is definitely more powerful, if you want it, this >>>>>> would probably be a good version of what you want that would handle >>>>>> multiple arguments: (I’ll reply again if I get one to work with >>>>>> optional and/or keyword-arguments) >>>>>> (define-syntax defpat >>>>>> (syntax-rules () >>>>>> [(defpat (f arg-pat ...) body ...) >>>>>> (defpat f (match-lambda** [(arg-pat ...) body ...]))] >>>>>> [(defpat id expr) >>>>>> (define id expr)])) >>>>> >>>>> Ok I just made a version of defpat that can handle multiple arguments, >>>>> optional arguments, keyword-arguments, and optional keyword-arguments. >>>>> I also made a form called my-match-lambda that defpat uses to do this. >>>>> https://github.com/AlexKnauth/defpat >>>>> Also to do this I had to make it so that you have to use square brackets >>>>> to specify optional arguments, otherwise it couldn’t tell between an >>>>> optional argument and a match pattern. >>>>> >>>> >>>> >>>> ____________________ >>>> Racket Users list: >>>> http://lists.racket-lang.org/users >> ____________________ Racket Users list: http://lists.racket-lang.org/users
