Thanks, that's perfect! I knew it couldn't have been overlooked :)
On Sun, Apr 7, 2013 at 5:31 PM, J. Ian Johnson <i...@ccs.neu.edu> wrote: > The ~in-between pattern and its specializations ~once and ~optional are > great for this purpose. Anything matching this pattern must appear in the > range given in ~in-between, even in ellipsis'd contexts. > (a:id b:id (~or (~once (~seq #:key1 c:id)) (~once (~seq #:key2 d:id))) ...) > > -Ian > > ----- Original Message ----- > From: "Scott Klarenbach" <sc...@pointyhat.ca> > To: "Racket mailing list" <users@racket-lang.org> > Sent: Sunday, April 7, 2013 8:23:29 PM GMT -05:00 US/Canada Eastern > Subject: [racket] Using syntax/parse, how to accept keyword arguments in > any order yet not allow duplicates? > > > > Hi there, > > > I'd like to create a macro that accepts non-optional keyword arguments in > any order. It should however, ensure that all the arguments are provided. > Finally, it should not allow duplicates. > > > So far I've only been able to solve for my first criteria. > > > As a test, I have this: > > > > (syntax-parse stx > [(a:id b:id (~or (~seq #:key1 c:id) (~seq #:key2 d:id)) ...) #t]) > > > Now, that matches for: > #'(a b #:key1 hey #:key2 there) > #'(a b #:key2 there #:key1 hey) > > > > Which is what I want. But unfortunately it also matches: > #'(a b #:key2 there) > > > And worse: > #'(a b #:key2 one #:key2 two #:key2 three) > > > The reasons are obvious. I'm just wondering if there's a more robust way > of dealing with these types of scenarios that I'm missing? I thought of > combining an (~or (~and clause but that becomes very tedious, and leaves > the duplicate problem unsolved. > > > Thanks. > > -- > Talk to you soon, > > Scott Klarenbach > > PointyHat Software Corp. > www.pointyhat.ca > p 604-568-4280 > e sc...@pointyhat.ca > 200-1575 W. Georgia > Vancouver, BC V6G2V3 > > _______________________________________ > To iterate is human; to recur, divine > ____________________ > Racket Users list: > http://lists.racket-lang.org/users > -- Talk to you soon, Scott Klarenbach PointyHat Software Corp. www.pointyhat.ca p 604-568-4280 e sc...@pointyhat.ca 200-1575 W. Georgia Vancouver, BC V6G2V3 _______________________________________ To iterate is human; to recur, divine
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