Re: [PATCH] Marking weak alist vectors, #2

[Ludovic Courtès]

Hi,

Han-Wen Nienhuys <address@hidden> writes:

> No, this is not cyclic. The problem is a situation where key A is 
> associated to key A, eg.
>
>   (define x (cons 1 2))
>   (set-cdr! x s)
>   (weak-key-hash-table-set! table s x)
>
> x points back to s, and s is a key in the table.

Ah, alright.  Well yes, the new patch does handle it, the previous one
didn't.  The issue at hand was similar to the one which showed up in my
"cascading weak keys" example.

  $ ../pre-inst-guile --no-debug
  guile> (use-modules (ice-9 weak-vector))
  guile> (define t (make-weak-key-alist-vector 12))
  guile> (define s (string-copy "chbouib"))
  guile> (hashq-set! t s (cons s 1))
  ("chbouib" . 1)
  guile> (set! s #f)
  guile> (gc)  
  guile> t
  #wh(() () () () () () () () () () () ())

Thanks,
Ludovic.