[heresy-devel] null/ bug.

[Robin Lee Powell]

On Tue, Sep 02, 2008 at 01:37:46PM -0700, Robin Lee Powell wrote:
> 
> IMO, membership predicates should never except, but:
> 
> * (null/ 'e)
> 
> debugger invoked on a SB-KERNEL:CASE-FAILURE in thread #<THREAD
> "initial thread" RUNNING {100266AC71}>: E fell through ETYPECASE
> expression. Wanted one of (LAZY-LIST HERESY::LAZY-LIST-KNOWN-EMPTY
> HERESY::LAZY-LIST-LIST-BASED SEQUENCE LIST).

This turns out to be a more serious problem than I thought;

(atom (list/ ))

returns t, so the obvious fix of

(or (atom x) (non-null/ x))

doesn't work.  On top of that, the "is a lazy list" predicate
doesn't seem to be exported from Heresy.  I had to add (atom nil) to
the etypecase for null/, but really I think that should be a
typecase with (t nil) at the end.

-Robin

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