Hi there,
I've got another problem with typed racket.
Let us say I have an assoc list with options for a program. These
options could be of type String, Boolean, or Integer.
Now in my program I want to check certain options but I don't know how
to do without Typed Racket screaming at me.
Here
Hi all,
I'm using Postgresql 9.3.5 and I keep getting a syntax error trying to
pass a list of identifiers to an in clause of a select.
(set! sql-cmd select * from contacts where id in $1 )
(set! result (query db sql-cmd (list 42 101)))
I've tried :
where id in $1
where id in
Well, I should have added that I've found this:
(: process (- OptList Void))
(define (process ol)
(let ([s (optval 'size ol)])
(if (and s ( (cast s Integer) 0))
(displayln wrong value)
(displayln ok)))
)
but I didn't find this really nice. Actually, I was hoping for
On Sun, 30 Nov 2014 09:25:57 -0500
Sam Tobin-Hochstadt sa...@cs.indiana.edu
wrote:
I think this is exactly what you need. You could write ( (assert s
integer?) 0) or (and s (integer? s) ( s 0)), which mostly do the same
thing.
But the fundamental issue is that this program is well-typed:
Hi all,
I've noticed that (find-system-path 'run-file) works differently under
the debugger vs the command line.
When I start an application from the command line - either as a linked
executable or as a script using racket file, (find-system-path
'run-file) gives me the start directory of
Have you considered this:
#lang typed/racket
(define-type Myopt (U String Boolean Integer))
(define-type OptList (Listof (Pairof Symbol Myopt)))
(: olist OptList)
(define olist
(list '(dir . .)
'(verbose . #t)
'(size . 12)))
; This is a fake type, where the filter flows
At Sun, 30 Nov 2014 16:38:02 +0100,
Manfred Lotz wrote:
1. You offered assert? as an alternative. Is this preferable in
comparison to cast?
Yes. Assertions are simple first order checks, and are quite
inexpensive. Casts, on the other hand, use contracts and may require
wrapping for mutable data
No I hadn't considered the variant using type?. Thanks for this.
Not quite sure if I'm happy about it as I would prefer to have the type
checking at one place instead of providing a type each time I check/use
options.
--
Manfred
On Sun, 30 Nov 2014 14:36:26 -0500
Matthias Felleisen
On Sun, 30 Nov 2014 15:26:09 -0500
Thanks, Vincent.
Vincent St-Amour stamo...@ccs.neu.edu
wrote:
At Sun, 30 Nov 2014 16:38:02 +0100,
Manfred Lotz wrote:
1. You offered assert? as an alternative. Is this preferable in
comparison to cast?
Yes. Assertions are simple first order checks, and
On Sun, 30 Nov 2014 22:21:14 +0100
Manfred Lotz manfred.l...@arcor.de wrote:
No I hadn't considered the variant using type?. Thanks for this.
Not quite sure if I'm happy about it as I would prefer to have the
type checking at one place instead of providing a type each time I
check/use
In terms of cost, that's identical to what I had __and__ it locks in the number
of variants you can deal with. In contrast, mine allows extensions at the point
where you define Myopt; for the new fields, just pass in the additional type
at the new call site.
Now if you are sure that the 15
I think you need define-runtime-path instead.
Here's an example of its use:
;; Access a file data.txt at run-time that is originally
;; located in the same directory as the module source file:
(define-runtime-path sofa.dll
(format sofa-~a-~a~a sofa-version arch ))
P.
On Sun, 30 Nov 2014 17:47:23 -0500
Matthias Felleisen matth...@ccs.neu.edu
wrote:
In terms of cost, that's identical to what I had __and__ it locks in
the number of variants you can deal with.
I agree that in terms of cost there is no difference. Yes, it locks in
the number of variants.
define-runtime-path looks like it will work for scripts. I haven't yet
understood how it interacts with creating a standalone executable - the
documentation is pretty dense so I guess I'll have to try it. But, at
least now I get the same result from a script under the debugger as when
run
Can I do `require` forms like this?
(require http://code_man.cybnet.ch/racket/3d-model.zip)
(require git://github.com/samth/abnf)
Neil V.
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