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 <[email protected]> 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 [email protected]. > > 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 [email protected]. > 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/20200601190913.hxaqlgfm7y6prm5p%40topoi.pooq.com.
