Re: [racket-users] syntax woe with typed Racket 'let'
On Mon, Jun 1, 2020 at 3:48 PM Sam Tobin-Hochstadt wrote: > (define (f [x : Number] . [y : String *]) : Number (+ x (length y))) > Another way to write this, which I often prefer, is: > (: f (-> Number String * Number)) > (define (f x . y) > (+ x (length y))) > -- 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/CAH3z3gZqMU8FGcCi6g165QhYsagjSoxkJS%2BXm%2BRi6Lpr2fbN7Q%40mail.gmail.com.
Re: [racket-users] syntax woe with typed Racket 'let'
On Mon, Jun 01, 2020 at 10:28:55PM -0500, Shu-Hung You wrote: > FWIW, because `.` is just cons, the program > (define (F [X : T1] . [Y : T2]) 'e) > is being read as: > (define (F [X : T1] Y : T2) 'e) > I guess that's the reason for having an extra '*' in the syntax. Indeed. It works for untyped Racket, but in typed Racket that notation would become quite ambiguous. -- hendrik > > On Mon, Jun 1, 2020 at 10:16 PM Sam Tobin-Hochstadt > wrote: > > > > The syntax looks like this: > > > > (define (f [x : Number] . [y : String *]) : Number (+ x (length y))) > > > > See the documentation for `define` in Typed Racket here: > > https://docs.racket-lang.org/ts-reference/special-forms.html?q=define#%28form._%28%28lib._typed-racket%2Fbase-env%2Fprims..rkt%29._define%29%29 > > in particular the `rst` production. > > > > Sam > > > > On Mon, Jun 1, 2020 at 3:09 PM Hendrik Boom wrote: > > > > > > 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 > > > > 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. > > > > > > >
Re: [racket-users] syntax woe with typed Racket 'let'
FWIW, because `.` is just cons, the program (define (F [X : T1] . [Y : T2]) 'e) is being read as: (define (F [X : T1] Y : T2) 'e) I guess that's the reason for having an extra '*' in the syntax. On Mon, Jun 1, 2020 at 10:16 PM Sam Tobin-Hochstadt wrote: > > The syntax looks like this: > > (define (f [x : Number] . [y : String *]) : Number (+ x (length y))) > > See the documentation for `define` in Typed Racket here: > https://docs.racket-lang.org/ts-reference/special-forms.html?q=define#%28form._%28%28lib._typed-racket%2Fbase-env%2Fprims..rkt%29._define%29%29 > in particular the `rst` production. > > Sam > > On Mon, Jun 1, 2020 at 3:09 PM Hendrik Boom wrote: > > > > 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 > > > 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. > >
Re: [racket-users] syntax woe with typed Racket 'let'
The syntax looks like this: (define (f [x : Number] . [y : String *]) : Number (+ x (length y))) See the documentation for `define` in Typed Racket here: https://docs.racket-lang.org/ts-reference/special-forms.html?q=define#%28form._%28%28lib._typed-racket%2Fbase-env%2Fprims..rkt%29._define%29%29 in particular the `rst` production. Sam On Mon, Jun 1, 2020 at 3:09 PM Hendrik Boom wrote: > > 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 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. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To
Re: [racket-users] syntax woe with typed Racket 'let'
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 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.
Re: [racket-users] syntax woe with typed Racket 'let'
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. Sam On Sat, May 30, 2020 at 1:32 PM Hendrik Boom 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.
[racket-users] syntax woe with typed Racket 'let'
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.
