I need to define syntax set!-values*, that will ignore _ in value place.
Such as
(define a #f)
(set!-values* (_ _ a) (values 1 2 3)) ; should set a to 3.
But I have two problems:
1. _ don't want to pattern match in syntax case. If I make it literal, I can't
match "anything else".
2. How to omit
FARM 2014
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Functional Art, Music, Modelling and Design
Gothenburg, Sweden; 6 September, 2014
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The ACM SIGPLAN International Workshop on Functional Art, M
On Fri, 27 Jun 2014 16:17:01 -0400
Sam Tobin-Hochstadt
wrote:
> On Fri, Jun 27, 2014 at 4:08 PM, Manfred Lotz
> wrote:
> > On Fri, 27 Jun 2014 15:59:47 -0400
> > "Alexander D. Knauth"
> > wrote:
> >
> >> Are you sure you meant "hash-ref!" and not just "hash-ref”?
> >>
> >
> > Well I thought has
Is this anything like what you wanted?
(require web-server/dispatch
(for-syntax syntax/parse
racket/list))
(begin-for-syntax
;; mdr-clause->dr-clauses : Syntax -> (Listof Syntax)
(define (mdr-clause->dr-clauses mdr-clause)
(syntax-parse mdr-clause
[[(th
On Fri, Jun 27, 2014 at 4:08 PM, Manfred Lotz wrote:
> On Fri, 27 Jun 2014 15:59:47 -0400
> "Alexander D. Knauth"
> wrote:
>
>> Are you sure you meant "hash-ref!" and not just "hash-ref”?
>>
>
> Well I thought hash-ref! is the way to go because I just wanted #f in
> case of not found.
>
>> Becaus
On Fri, 27 Jun 2014 15:59:47 -0400
"Alexander D. Knauth"
wrote:
> Are you sure you meant "hash-ref!" and not just "hash-ref”?
>
Well I thought hash-ref! is the way to go because I just wanted #f in
case of not found.
> Because even with (hash-ref! my-hash size (lambda () #f)), it would
> expec
I think you should follow Alexander's advice here about using
`hash-ref` and not `hash-ref!`.
Also, your whole function can also be written as:
(hash-update! my-hash size (λ ([v : (Listof String)]) (cons s v))
(λ () null))
Sam
On Fri, Jun 27, 2014 at 3:55 PM, Manfred Lotz wrote:
> On Fri,
On Fri, 27 Jun 2014 15:49:14 -0400
Sam Tobin-Hochstadt
wrote:
> On Fri, Jun 27, 2014 at 3:32 PM, Manfred Lotz
> wrote:
> >
> > Argument 3:
> > Expected: (-> b)
> > Given:False
>
>
> This is the key part of the error message: you have to provide a
> function as the third argument, and y
Are you sure you meant "hash-ref!" and not just "hash-ref”?
Because even with (hash-ref! my-hash size (lambda () #f)), it would expect the
#f to be of type (Listof String), which it isn’t.
On Jun 27, 2014, at 3:32 PM, Manfred Lotz wrote:
> I tried this:
>
> #lang typed/racket/base
>
> (: m
On Fri, Jun 27, 2014 at 3:32 PM, Manfred Lotz wrote:
>
> Argument 3:
> Expected: (-> b)
> Given:False
This is the key part of the error message: you have to provide a
function as the third argument, and you provided `#f`. I'd just change
that to (lambda () #f).
Sam
I'm working with some servlet dispatching code and I want to be able to use
dispatch-rules to generate the url to response mappings, but I want to be
able to group related handlers to subpages. Under dispatch-rules, that
looks something like this:
(dispatch-rules
[("page-a" "handler-a" (intege
I tried this:
#lang typed/racket/base
(: my-hash (HashTable Nonnegative-Integer (Listof String)))
(define my-hash (make-hash))
(: my-hash-add (-> Nonnegative-Integer String Void))
(define (my-hash-add size s)
(let* ([val (hash-ref! my-hash size #f)])
(if val
(hash-set! my-hash si
I tried this:
#lang typed/racket/base
(: my-hash (HashTable Nonnegative-Integer (Listof String)))
(define my-hash (make-hash))
(: my-hash-add (-> Nonnegative-Integer String Void))
(define (my-hash-add size s)
(let* ([val (hash-ref! my-hash size #f)])
(if val
(hash-set! my-hash si
I tried this:
#lang typed/racket/base
(: my-hash (HashTable Nonnegative-Integer (Listof String)))
(define my-hash (make-hash))
(: my-hash-add (-> Nonnegative-Integer String Void))
(define (my-hash-add size s)
(let* ([val (hash-ref! my-hash size #f)])
(if val
(hash-set! my-hash si
I used Scala for our intro course last year, mostly because I wanted types.
I know Matthias thinks types are a horrible thing to make students deal
with first semester, but I found that students made different kinds of
mistakes than they did in Racket. When you're writing containsDoll and the
syste
On Fri, 27 Jun 2014 14:04:46 -0400
Sam Tobin-Hochstadt
wrote:
> You should use `(require typed/racket/date)` instead.
>
Great.
> There's a list of already-typed libraries in the documentation here:
> http://docs.racket-lang.org/ts-reference/Libraries_Provided_With_Typed_Racket.html
> but I see
You should use `(require typed/racket/date)` instead.
There's a list of already-typed libraries in the documentation here:
http://docs.racket-lang.org/ts-reference/Libraries_Provided_With_Typed_Racket.html
but I see that it doesn't mention `racket/date`.
Sam
On Fri, Jun 27, 2014 at 1:49 PM, Manf
I would write the program this way:
#lang typed/racket
(: exit-with-error-msg : String Any * -> Any)
(define (exit-with-error-msg m . e)
(apply eprintf m e)
(exit 1))
Note that we explicitly require at least one argument, the format
string. In your program, Typed Racket can't tell that
On Fri, 27 Jun 2014 13:55:52 -0400
Sam Tobin-Hochstadt
wrote:
> I would write the program this way:
>
> #lang typed/racket
>
> (: exit-with-error-msg : String Any * -> Any)
> (define (exit-with-error-msg m . e)
> (apply eprintf m e)
> (exit 1))
>
> Note that we explicitly require at le
Hi there,
In order to use racket/date in a typed racket program do I need to use
(require/typed ...)?
If understand it right I have to define types for the stuff I use from
racket/date. Is this true?
--
Manfred
Racket Users list:
http://lists.racket-lang.org/users
I have this:
(define (exit-with-error-msg . e)
(apply eprintf e)
(exit 1))
When using it with typed racket I get:
test.rkt:127:4: Type Checker: Bad arguments to function in apply:
Domain: String Any *
Arguments: (Listof Any) *
in: (apply eprintf e)
context...:
/home/manfred/rac
On 2014-06-26, 1:29 AM, users-requ...@racket-lang.org wrote:
I heard Cornell and Harvard use OCaml, of all things. . . .
Cornell appears to use Python and MATLAB in their first courses; I don't
see OCaml until third year. Harvard uses OCaml in a second course; C,
PHP, Javascript in a first.
On Wed, Jun 25, 2014 at 08:49:32PM -0500, Lawrence Bottorff wrote:
> I see a huge differential between the high quality of Racket and the fact
> that its popularity is low. Then again, perhaps Racket is where Python was
> ten years ago, i.e., more than ready for prime-time, "batteries included,"
>
ILC 2014 - International Lisp Conference
"Lisp on the Move"
August 15-17 2014, Université de Montréal, Montréal, Canada
Sponsored by the Association of Lisp Users
In cooperation with: ACM SIGPLAN
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