I assume it wouldn't be too difficult, and that it's worth doing even if it doesn't solve this particular problem. Can someone grant me commit privileges?<div> </div><div><div class="gmail_quote">On Thu, Jan 19, 2012 at 5:18 AM, Matthew Flatt <<a href="mailto:mflatt@cs.utah.edu">mflatt@cs.utah.edu</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">(Just to be clear, that wouldn't solve the problem this time. The `=' from `scheme' and `racket' are the same, but `frtime' has its own `='.) <div class="HOEnZb"><div class="h5"> At Thu, 19 Jan 2012 08:19:59 -0500, Matthias Felleisen wrote: > > Greg, how difficult would it be to migrate frtime to #lang racket? -- Matthias > > > > On Jan 19, 2012, at 8:13 AM, Matthew Flatt wrote: > > > The `frtime' language exports an `=' that isn't the same as `=' in > > `racket', so that's why the pattern doesn't match. (This seems like a > > further weakness of the `frtime' docs to specify the exports > > precisely.) > > > > You could avoid bound names like `=' as literals in the macro. > > Normally, it works best for a form-exporting macro to also export > > bindings for any literals in the form. Otherwise, this kind of > > confusion is common. > > > > Alternatively, you may want to match literals in your macro > > symbolically instead of by binding. You can't do that easily with > > `syntax-rules', but you can use `syntax-case*' and supply `(lambda (a > > b) (eq? (syntax-e a) (syntax-e b)))' as the literal-comparison > > function. > > > > If it were me and I decided to go in the direction of symbol equality, > > I'd use keywords instead --- `#:?' and `#:=' instead of `?' and `=' --- > > which makes clear that there's no question of binding. > > > > > > At Thu, 19 Jan 2012 10:46:37 +0100, Marijn wrote: > >> On 18-01-12 17:47, Matthew Flatt wrote: > >>> At Wed, 18 Jan 2012 12:02:10 +0100, Marijn wrote: > >>>> I would expect both forms to work. This is a reduction of a different > >>>> problem possibly caused by these issues here. > >> > >> So I tried to cut down my program to a reasonably sized test-case which > >> is attached to this email. model.rkt contains (what's left of) the model > >> macro, demo1.rkt contains a small model and a (require frtime). If you > >> do "racket demo1.rkt" then you get the following error: > >> > >> > >> model.rkt:30:17: make-entry: bad syntax in: (make-entry (= profit > >> (for/hash ((y years)) (values y (- (hash-ref income y 0) (hash-ref > >> expenses y 0))))) (years income expenses profit)) > >> > >> === context === > >> standard-module-name-resolver > >> > >> > >> but if you comment the (require frtime) then the error goes away. I have > >> other code that tests this same simple-economy model with the > >> non-cutdown version of the model macro and supporting code and > >> everything seems to work fine. > >> > >> Any idea what's going on here? > >> > >> Marijn > >> > >> > ------------------------------------------------------------------------------ > >> [text/plain "demo1.rkt"] [~/Desktop & open] [~/Temp & open] > >> > >> > ------------------------------------------------------------------------------ > >> [text/plain "model.rkt"] [~/Desktop & open] [~/Temp & open] > >> > >> > ------------------------------------------------------------------------------ > >> [application/pgp-signature "signature.asc"] [~/Desktop & open] [~/Temp & > open] > > _________________________ > > Racket Developers list: > > <a href="http://lists.racket-lang.org/dev" target="_blank">http://lists.racket-lang.org/dev</a> _________________________ Racket Developers list: <a href="http://lists.racket-lang.org/dev" target="_blank">http://lists.racket-lang.org/dev</a> </div></div></blockquote></div> </div>