> 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. > 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? > 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
