Re: Scheme bug in internal define

From: Erick Gallesio <eg_at_kaolin.unice.fr>
Date: Wed, 19 Nov 1997 11:46:54 +0100

Keith Wright writes:
> The following program exhibits a bug in both STk and Guile.
> (Somebody ought to try it on SCM.)
> One would expect it either to print "good" twice, or
> to display an error message. In fact it prints "good"
> and then "bad". MIT scheme prints "good" twice.
> I have STk-3.1 and guile-core-971005.
>
> (define (bug)
> (define good "good")
> (define bad "bad")
> (define (do-good) (display good)(newline))
> (do-good)
> (define ugly #f)
> (do-good))
> (bug)
>

This bug is now corrected. STk behaviour is now identical to MIT Scheme
(even if a pure R4RS system should declare this program erroneous. OK, let's
state this behaviour as an extension and the problem disappear :-)

                -- Erick
Received on Wed Nov 19 1997 - 12:13:51 CET