[racket-dev] 'case' using equal?

Thanks! With that approach, I can get it to build. -J

On Sun, Nov 25, 2012 at 10:11 PM, Robby Findler
<robby at eecs.northwestern.edu> wrote:
> I'm not sure what that error message means, but I think I was thinking
> of a different strategy. Something like this (but where you deal with
> 'else' properly and write in '#%kernel (so you have to use the
> expansion of log-info etc etc)), all staying in the same file.
>
> #lang racket
> (provide (rename-out [new:case case]))
> (define-syntax (new:case stx)
>   (with-syntax ([line (syntax-line stx)]
>                 [fn (syntax-source stx)])
>     (syntax-case stx ()
>       [(_ exp [(d ...) exp ...])
>        #'(let ([x exp])
>            (check-em 'fn line x '(d ... ...))
>            (case exp [(d ...) exp ...] ...))])))
>
> (define (check-em file line val datums)
>   (for ([datum (in-list datums)])
>     (unless (eq? (equal? datum val)
>                  (eqv? datum val))
>       (log-info
>        (format "found a difference in ~a:~a; ~s vs ~s"
>                file line datum val)))))
>
> Robby
>
> On Sun, Nov 25, 2012 at 8:57 PM, Jon Zeppieri <zeppieri at gmail.com> wrote:
>> On Sun, Nov 25, 2012 at 7:49 PM, Jon Zeppieri <zeppieri at gmail.com> wrote:
>>>
>>> Looking back at the users thread, I see what you mean. I'll create a
>>> branch that will do what you suggest: evaluate the expression both
>>> ways, compare, and complain if the results differ.
>>>
>>
>> This is not turning out to be as simple as expected.
>>
>> I created modules equal-case.rkt and eqv-case.rkt, and then a simple
>> case macro in case.rkt that uses both. However, the build fails at:
>>
>> make xsrc/precomp.h
>> env XFORM_PRECOMP=yes ../racketcgc -cqu ../../../racket/gc2/xform.rkt
>> --setup . --cpp "gcc -E -I./.. -I../../../racket/gc2/../include -DOS_X
>> -D_DARWIN_UNLIMITED_SELECT -pthread  -fno-common   "  --keep-lines -o
>> xsrc/precomp.h ../../../racket/gc2/precomp.c
>> /Users/jaz/src/racket/collects/s-exp/lang/reader.rkt:1:36:
>> syntax/module-reader: got two #:language keywords
>>   in: #:language
>>   context...:
>>    /Users/jaz/src/racket/collects/syntax/module-reader.rkt:19:14: loop
>>    /Users/jaz/src/racket/collects/syntax/module-reader.rkt:35:4:
>> construct-reader
>>    standard-module-name-resolver
>>    standard-module-name-resolver
>>    standard-module-name-resolver
>>    /Users/jaz/src/racket/src/racket/gc2/xform.rkt:95:24
>>    /Users/jaz/src/racket/src/racket/gc2/xform.rkt: [running body]
>> make[4]: *** [xsrc/precomp.h] Error 1
>> make[3]: *** [all] Error 2
>> make[2]: *** [3m] Error 2
>> make[1]: *** [3m] Error 2
>> make: *** [all] Error 2