On Mon, Jun 01, 2020 at 10:58:09AM -0400, Sam Tobin-Hochstadt wrote: > Do you perhaps have some other binding shadowing the binding of `:` > from Typed Racket? That produces the error message you get when I try > it.
Not intentionally. I'll have to look carefully for possible candidates. Or ask DrRacket to jump to a binding occurrence. Did that: It wouldn't find a bining instance while that colon was there, but complained about the syntax error I was sompaining about. But when I removed the type specification from the let-clause and introuced a colon elsewhere in the function as an extra parameter in another expression, it would find the binding. It turned out that the binding occurrence was the colon in the tail-parameter [args : T-Size]. So I have to ask, what *is* the proper way to indicate that the function can be called with many more parameters, which are to be made available as a list? Thank you for the hint. -- hendrik > > Sam > > On Sat, May 30, 2020 at 1:32 PM Hendrik Boom <hend...@topoi.pooq.com> wrote: > > > > I'm sorry to keep pestering this list, but I'm out of my depth with the > > detailed syntax (and semantics) of typed Racket. But I'm doggedly > > ploughing on. > > > > I'm having trouble with the 'let' line in the 'pointer-to' function listed > > later: > > > > (let ([vt : Ffi-type (cast ((inst hash-ref Ffi-type Ffi-type) > > type-to-vector type #f) Ffi-type)]) > > > > Yes, there's an unbalanced parenthesis because this sin't the end of the > > let-expression. > > > > The error message is > > > > let: expected type-annotated identifier > > parsing context: > > while parsing annotated-binding > > while parsing optionally type-annotated binding in: (vt : Ffi-type (cast > > ((inst hash-ref Ffi-type Ffi-type) type-to-vector type #f) Ffi-type)) > > > > I can't see the error. 'vt : Ffi-type' looks like a type-annotated > > identifier to me. And it seems to have the right number of parentheses > > in front of it, followed by an expression whose vlue is to be bound to > > 'vt'. > > > > Here's the function it's part of: > > > > > > (define (pointer-to [type : T-Type] . [args : T-Size]) : T-Type ; TODO: > > rename args to size-args > > (if (and (equal? args '(1)) (not (eq? type '_void))) > > (mode-dependent-type > > `(_ptr i ,type) `(_ptr o ,type)) > > (case type > > ((_void) '_pointer/intptr) > > ((_byte _uint8) (mode-dependent-type > > '_string*/utf-8 > > (if (null? args) > > '_bytes > > `(_bytes o ,@ args)))) > > (else > > (let ([vt : Ffi-type (cast ((inst hash-ref Ffi-type Ffi-type) > > type-to-vector type #f) Ffi-type)]) > > (if vt > > (mode-dependent-type > > `(,vt i) > > (if (null? args) > > vt > > `(,vt o ,@ args))) > > (mode-dependent-type > > `(_vector i ,type) > > (if (null? args) > > '_pointer > > `(_vector o ,type ,@ args))))))))) > > > > -- > > 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/20200530173230.bsrp5skkc35ot34h%40topoi.pooq.com. > > -- > 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/CAK%3DHD%2BYkANXdevMc%3DiSTFaWnpzU-6ofNWF2qJtWyR-f6ES2gLg%40mail.gmail.com. -- 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/20200601190913.hxaqlgfm7y6prm5p%40topoi.pooq.com.
