On Thursday, December 10, 2015 at 7:15:07 PM UTC+1, Jonathan Brachthäuser wrote: > In DrRacket 6.2.1 when using the `match` construct as defined in the > abstraction teachpack together with posn a strange problem appears. > > When choosing BSL as language the following code just works as expected: > > ``` > (require 2htdp/abstraction) > (match (make-posn 1 2) [(posn x y) (+ x y)]) > ``` > > yields `3`. > > However when choosing "BSL with list abbreviation" the above code gives: > > ``` > ... (posn x y) ... > function call: expected a function after the open parenthesis, but found a > part > ``` > > We can work around the error by using `my-posn` instead (defined below) > > ``` > (define-struct my-posn (x y)) > ``` > > Is there any explanation why this happens? Is the abstraction teachpack not > designed to work with "BSL with list abbrv" ?
The issue is a missing export in BSL+. Last time this came up, I submitted a pull request which is still open, so I suspect this isn't fixed yet: https://github.com/racket/htdp/pull/16. Apparently I only made a pull request and didn't open a thread on this ML, which might be part of the problem. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
