Glad it was useful! There is a variant `in-value*/expression` that works like your `in-values`: https://docs.racket-lang.org/adjutor/Stable.html#(form._((lib._adjutor%2Fmain..rkt)._in-value*%2Fexpression))
-Philip On Mon, May 4, 2020 at 10:12 PM Jos Koot <jos.k...@gmail.com> wrote: > To Philip McGrath, Hi again > > > > I modified the clause > > ((id ...) (in-value* expr ...)) > > to the following in-values clause: > > ((id ...) (in-values expr)) > > > > where the expr is supposed to return as many values as ids. > > I simplified the code such as to avoid syntax-parse, > > because I do not (yet) understand all its powerful features. > > I prefer writing code I can understand in all details. > > 😉 I should study on syntax-parse in due future 😉 > > > > (define-sequence-syntax in-values > > (λ (stx) > > (raise-syntax-error 'in-values > > "can only be used in for forms" stx)) > > (λ (stx) > > (syntax-case stx () > > (((id ...) (_ expr)) > > #'((id ...) > > (:do-in > > (((id ...) expr)) > > #t () #t () #t #f ())))))) > > > > For example: > > > > (for/first (((a b c) (in-values (values 2 + 3)))) (b a c)) ; -> 5 > > > > Thanks again, Jos > > > > *From: *Philip McGrath <phi...@philipmcgrath.com> > *Sent: *04 May 2020 17:21 > *To: *Jos Koot <jos.k...@gmail.com> > *Cc: *us...@racket-lang.org > *Subject: *Re: [racket-users] multiple-value version of in-value > > > > My package `adjutor` has a few variants of this, like `in-value*`: > https://docs.racket-lang.org/adjutor/Stable.html#(part._.Sequence_.Constructors) > > > > They can all be used as first-class procedures, but that does involve a > little runtime overhead, so they use `define-sequence-syntax` to cooperate > directly with `for`-like forms when possible. > > > > -Philip > > > > > > > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/CAH3z3gZdxzaUgWqqhM4PzYT%3DozckGrUsaHh8OXFDH74mfEutHg%40mail.gmail.com.
