* bug#21897: escape continuation passes barrier
@ 2015-11-13 3:31 Zefram
2016-06-24 16:23 ` Andy Wingo
2020-03-29 17:28 ` bug#21897: verified in 3.0.2 Matt Wette
0 siblings, 2 replies; 3+ messages in thread
From: Zefram @ 2015-11-13 3:31 UTC (permalink / raw)
To: 21897
scheme@(guile-user)> (use-modules (ice-9 control))
scheme@(guile-user)> (call/ec (lambda (c) (with-continuation-barrier (lambda () (c "through continuation"))) "c-w-b returned"))
$1 = "through continuation"
The continuation barrier works fine on call/cc continuations and
on throw/catch, but doesn't block call/ec continuations. The manual
doesn't mention any difference in behaviour for this case, nor can I
see any obvious justification for it. The manual's statement that
# Thus, `with-continuation-barrier' returns exactly once.
is false in this case. I think a continuation barrier should block the
use of the call/ec continuation.
-zefram
^ permalink raw reply [flat|nested] 3+ messages in thread
* bug#21897: escape continuation passes barrier
2015-11-13 3:31 bug#21897: escape continuation passes barrier Zefram
@ 2016-06-24 16:23 ` Andy Wingo
2020-03-29 17:28 ` bug#21897: verified in 3.0.2 Matt Wette
1 sibling, 0 replies; 3+ messages in thread
From: Andy Wingo @ 2016-06-24 16:23 UTC (permalink / raw)
To: Zefram; +Cc: 21897
On Fri 13 Nov 2015 04:31, Zefram <zefram@fysh.org> writes:
> scheme@(guile-user)> (use-modules (ice-9 control))
> scheme@(guile-user)> (call/ec (lambda (c) (with-continuation-barrier (lambda () (c "through continuation"))) "c-w-b returned"))
> $1 = "through continuation"
>
> The continuation barrier works fine on call/cc continuations and
> on throw/catch, but doesn't block call/ec continuations. The manual
> doesn't mention any difference in behaviour for this case, nor can I
> see any obvious justification for it. The manual's statement that
>
> # Thus, `with-continuation-barrier' returns exactly once.
>
> is false in this case. I think a continuation barrier should block the
> use of the call/ec continuation.
I agree, good catch.
Andy
^ permalink raw reply [flat|nested] 3+ messages in thread
* bug#21897: verified in 3.0.2
2015-11-13 3:31 bug#21897: escape continuation passes barrier Zefram
2016-06-24 16:23 ` Andy Wingo
@ 2020-03-29 17:28 ` Matt Wette
1 sibling, 0 replies; 3+ messages in thread
From: Matt Wette @ 2020-03-29 17:28 UTC (permalink / raw)
To: 21897
This still exists in 3.0.2
scheme@(guile-user)> ,use (ice-9 control)
scheme@(guile-user)> (call/ec (lambda (c) (with-continuation-barrier (lambda () (c "through continuation"))) "c-w-b returned"))
$1 = "through continuation"
scheme@(guile-user)> (version)
$2 = "3.0.2"
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-11-13 3:31 bug#21897: escape continuation passes barrier Zefram
2016-06-24 16:23 ` Andy Wingo
2020-03-29 17:28 ` bug#21897: verified in 3.0.2 Matt Wette
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