severity 455702 wishlist thanks Thanks for the bug report.
R5RS Scheme does not require signalling errors at all for a values mismatch; so the behavior of a program which generates one is strictly undefined. Not all errors are required to be signalled, and in R5RS, virtually none are. I've discussed this with upstream, and the consensus seems to be that if it can be done efficiently, it would be nice if values mismatches were reliably signalled. However, because SCM isn't incorrect as it is, I'm reclassifying this bug report as a wishlist item. Thomas On Tue, 2007-12-11 at 09:37 +0000, Barak A. Pearlmutter wrote: > Package: scm > Version: 5e3-6 > Severity: normal > > There is a problem with error detection in the use of the VALUES > procedure with other than one argument in a context where a single > value is expected. As seen in the transcript below, the failure mode > changes depending on the number of such calls and other aspects of > their context. > -- > Barak A. Pearlmutter > Hamilton Institute & Dept Comp Sci, NUI Maynooth, Co. Kildare, Ireland > http://www.bcl.hamilton.ie/~barak/ > > $ scm > SCM version 5e3, Copyright (C) 1990-2002 Free Software Foundation. > SCM comes with ABSOLUTELY NO WARRANTY; for details type `(terms)'. > This is free software, and you are welcome to redistribute it > under certain conditions; type `(terms)' for details. > ;loading /usr/share/slib/require > ;done loading /usr/share/slib/require.scm > ;loading /usr/share/slib/require > ;done loading /usr/share/slib/require.scm > ;loading /usr/lib/scm/Link > ;done loading /usr/lib/scm/Link.scm > ;loading /usr/lib/scm/Transcen > ;done loading /usr/lib/scm/Transcen.scm > > (values 'a 'b) > a > b > > 'a > a > > (list 'a (values 'b 'c) 'd) > (a b d) > c > > (list 'a (list 'b (values 'c 'd) 'e) 'f) > (a (b c e) f) > d > > (list 'a (values 'b 'c 'd) 'e) > (a b e) > c > d > > (list 'a (values 'b 'c) (values 'd 'e) 'f) > > ;ERROR: "/usr/lib/scm/Iedline.scm": values: one value expected > ; in expression: ([EMAIL PROTECTED] ([EMAIL PROTECTED] d) ([EMAIL PROTECTED] > e)) > ; in top level environment. > ;STACK TRACE > 1; ([EMAIL PROTECTED] ([EMAIL PROTECTED] a) ([EMAIL PROTECTED] ([EMAIL > PROTECTED] b) ([EMAIL PROTECTED] c)) ([EMAIL PROTECTED] ... > > > (list 'a (values) 'b (values) 'c) > (a #<undefined> b #<undefined> c) > > (list 'a (values 'b 'c) 'd (values 'e) 'f) > (a b d e f) > c > > (list 'a (values) 'b (values 'c 'd) 'e) > (a #<undefined> b c e) > d > > (list 'a (values 'b 'c) 'd (values) 'e) > > ;ERROR: "/usr/lib/scm/Iedline.scm": values: one value expected > ; in expression: ([EMAIL PROTECTED]) > ; in top level environment. > ;STACK TRACE > 1; ([EMAIL PROTECTED] ([EMAIL PROTECTED] a) ([EMAIL PROTECTED] ([EMAIL > PROTECTED] b) ([EMAIL PROTECTED] c)) ([EMAIL PROTECTED] ... > > -- System Information: > Debian Release: 4.0 > APT prefers stable > APT policy: (500, 'stable'), (150, 'testing'), (100, 'unstable'), (50, > 'experimental') > Architecture: i386 (x86_64) > Shell: /bin/sh linked to /bin/bash > Kernel: Linux 2.6.22-3-amd64 > Locale: LANG=en_IE, LC_CTYPE=en_IE (charmap=ISO-8859-1) > > Versions of packages scm depends on: > ii libc6 2.3.6.ds1-13etch2 GNU C Library: Shared libraries > ii libncurses5 5.5-5 Shared libraries for terminal > hand > ii libreadline5 5.2-2 GNU readline and history > libraries > ii libx11-6 2:1.0.3-7 X11 client-side library > ii slib 3a4-4 Portable Scheme library > > scm recommends no packages. > > -- no debconf information > > -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
