[plt-dev] define-match-expander <-> unlib.plt doesn't compile

From: Dave Gurnell (d.j.gurnell at gmail.com)
Date: Fri Nov 13 04:19:51 EST 2009

John Clements wrote:
> Dave Gurnell wrote:
>> I've uploaded Unlib 3.19 containing a fix for the match problem.
> Awesome fixed now thanks all.

Hi all,

I haven't managed to fix this in its entirety and I'm not sure how to  
go about it correctly.

The eq? match expander now looks like this:

; (_ expr pattern ...)
(define-match-expander match:eq?
   (lambda (stx)
     (syntax-case stx ()
       [(_ expr pattern ...)
        #'(? (cut eq? <> expr) pattern ...)]))
   (lambda (stx)
     (syntax-case stx ()
       [_ #'eq?])))

However, the second transformer procedure only works if eq? is in  
application position. Looking at the docs, I assume I want to use make- 
rename-transformer in some way but I can't work out how in this context.

Can anyone offer any pointers?

Many thanks,

-- Dave

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