* [bug #31445] Incorrect multiple-value truncation [1.9.13] @ 2010-10-25 9:57 Ludovic Courtès 2010-11-18 19:35 ` Andy Wingo 0 siblings, 1 reply; 4+ messages in thread From: Ludovic Courtès @ 2010-10-25 9:57 UTC (permalink / raw) To: Ludovic Courtès, bug-guile URL: <http://savannah.gnu.org/bugs/?31445> Summary: Incorrect multiple-value truncation [1.9.13] Project: Guile Submitted by: civodul Submitted on: Mon 25 Oct 2010 09:57:33 AM GMT Category: None Severity: 3 - Normal Item Group: None Status: None Privacy: Public Assigned to: None Open/Closed: Open Discussion Lock: Any _______________________________________________________ Details: This is with `map' implemented in C: #v+ scheme@(guile-user)> (map (lambda (x) (values x x)) (iota 2)) $5 = (#<values (0 0)> #<values (1 1)>) scheme@(guile-user)> ,x map Disassembly of #<procedure map (_ _ . _)>: 0 (assert-nargs-ge 0 2) 3 (push-rest 0 2) 6 (object-ref 0) ;; #<pointer 0x7f4ee0395d20> 8 (subr-call 3) #v- Instead, the result should be '(0 1). Conversely: #v+ scheme@(guile-user)> (map (lambda (x) (identity (values x x))) (iota 2)) $6 = (0 1) scheme@(guile-user)> ,x identity Disassembly of #<procedure identity (x)>: 0 (assert-nargs-ee/locals 1) 2 (local-ref 0) ;; `x' 4 (return) #v- _______________________________________________________ Reply to this item at: <http://savannah.gnu.org/bugs/?31445> _______________________________________________ Message sent via/by Savannah http://savannah.gnu.org/ ^ permalink raw reply [flat|nested] 4+ messages in thread
* [bug #31445] Incorrect multiple-value truncation [1.9.13] 2010-10-25 9:57 [bug #31445] Incorrect multiple-value truncation [1.9.13] Ludovic Courtès @ 2010-11-18 19:35 ` Andy Wingo 2010-11-18 21:31 ` Ludovic Courtès 0 siblings, 1 reply; 4+ messages in thread From: Andy Wingo @ 2010-11-18 19:35 UTC (permalink / raw) To: Ludovic Courtès, Andy Wingo, bug-guile Follow-up Comment #1, bug #31445 (project guile): This is not a regression, as the results would have been the same before 1.9. But clearly it's not ideal either. I propose we add new API, scm_call_0_v, scm_apply_3_v, etc. Such code would truncate or raise an error for 0 values. Then we change all internal users to use the new code, if appropriate. WDYT? _______________________________________________________ Reply to this item at: <http://savannah.gnu.org/bugs/?31445> _______________________________________________ Message sent via/by Savannah http://savannah.gnu.org/ ^ permalink raw reply [flat|nested] 4+ messages in thread
* [bug #31445] Incorrect multiple-value truncation [1.9.13] 2010-11-18 19:35 ` Andy Wingo @ 2010-11-18 21:31 ` Ludovic Courtès 2010-11-19 15:39 ` Andy Wingo 0 siblings, 1 reply; 4+ messages in thread From: Ludovic Courtès @ 2010-11-18 21:31 UTC (permalink / raw) To: Ludovic Courtès, Andy Wingo, bug-guile Follow-up Comment #2, bug #31445 (project guile): Hmm, maybe that's a complex solution for a situation that'll be less and less common, especially when `map' & co. are rewritten in Scheme. WDYT? _______________________________________________________ Reply to this item at: <http://savannah.gnu.org/bugs/?31445> _______________________________________________ Message sent via/by Savannah http://savannah.gnu.org/ ^ permalink raw reply [flat|nested] 4+ messages in thread
* [bug #31445] Incorrect multiple-value truncation [1.9.13] 2010-11-18 21:31 ` Ludovic Courtès @ 2010-11-19 15:39 ` Andy Wingo 0 siblings, 0 replies; 4+ messages in thread From: Andy Wingo @ 2010-11-19 15:39 UTC (permalink / raw) To: Ludovic Courtès, Andy Wingo, bug-guile Follow-up Comment #3, bug #31445 (project guile): I could go either way. I think using a single-valued, truncating API is the right thing to do though. Grep your tree for scm_call_ and scm_apply to see the size of the set of current use cases. _______________________________________________________ Reply to this item at: <http://savannah.gnu.org/bugs/?31445> _______________________________________________ Message sent via/by Savannah http://savannah.gnu.org/ ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2010-11-19 15:39 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2010-10-25 9:57 [bug #31445] Incorrect multiple-value truncation [1.9.13] Ludovic Courtès 2010-11-18 19:35 ` Andy Wingo 2010-11-18 21:31 ` Ludovic Courtès 2010-11-19 15:39 ` Andy Wingo
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