[plt-scheme] match question

On Mon, May 12, 2008 at 11:34 PM, praimon <praimon at gmail.com> wrote:
> thanks for your response. Would you say that the greediness of
>  the patterns produces counter-intuitive answers?
>  Here's a very simple example:
>
>  (match '(3 2 4 3 2 1)
>        ((list x y ... x z ...) (append y z)))
>  => (2 4 3 2)
>
>  Surely the result should be (2 4 2 1)? At least that's the intuitively
>  correct answer (and the one returned by Mathematica, e.g.).
>
>  Changing ... to ..1 produces a different counter-intuitive answer: (2 4 3 1).
>  For people like me, who are merely using your language rather than trying
>  to understand its inner workings, this is worrisome.

Neither of those are the right answer.  There seems to be something
wrong with non-linear patterns (patterns where a variable appears
multiple times, like `x' does here) combined with ...  I'll take a
look at it.

If you could file a bug report with that example (see the "Submit Bug
Report" entry under the Help menu) that would be great.

Thanks,
-- 
sam th
samth at ccs.neu.edu