[racket] Check Syntax arrows for #lang languages

This is the function you want, I think:

+
+(define (sym->original-syntax sym srcloc)
+  (define p (open-input-string (symbol->string sym)))
+  (port-count-lines! p)
+  (match-define (list source-name line column position span) srcloc)
+  (set-port-next-location! p line column position)
+  (read-syntax source-name p))

On Tue, Jul 3, 2012 at 12:44 PM, Jens Axel Søgaard
<jensaxel at soegaard.net> wrote:
> 2012/7/3 Robby Findler <robby at eecs.northwestern.edu>
>>
>> Another possibility is that the identifiers that your reader produces
>> are not syntax-original?. You have to use 'read-syntax' to actually
>> produce the identifiers to get that mark on them.
>
>
> That's definitely it. But since I am not using read-syntax,
> how do I get the right mark? The docs for syntax-original?
> says
>
>     Returns #t if stx has the property that read-syntax attaches to
> thesyntax objects
>     that they generate  ...
>
> So it is not clear what property I should set in my own read-syntax.
>
> I have specified my own read-syntax in lang/reader.rkt.
> The reader uses the source location lexer/parser from the
> parser location and then wraps result in a module.
>
> https://github.com/soegaard/bracket/blob/master/bracket/lang/reader.rkt
>
>>
>> There are some unreleased changes to datalog that improve this aspect of
>> it:
>>
>>
>> http://git.racket-lang.org/plt/commit/bf95ee10523daabea4925073ff035bf57ecad59f
>>
>> there are few followup commits that clean up that one but not, I
>> think, relating to this issue.
>
>
> I see a few changes in order to store the source location in the tokens,
> but I am already doing that - and error messages find the proper places
> so it seems that part works.
>
> https://github.com/soegaard/bracket/blob/master/bracket/lang/parser.rkt
>
> /Jens Axel
>