I'm so glad for all the people who intervened in this discussion
As this made the subtleties of the issue clearer.
Thank you people !
2017-07-09 16:49 GMT+02:00 Chris Vine :
> On Sun, 9 Jul 2017 11:09:25 -0300
> Vítor De Araújo wrote:
>
> unwind-protect is a dynamic-wind wit
t;
> >> Trouble is, Scheme's continuations make it impossible to know when
> >> something is really final.
> >>
> >> In fact, implementing coroutines and cooperative multitasking using
> >> continuations almost guarantee a repeated back-and-fort
gt; something is really final.
>>
>> In fact, implementing coroutines and cooperative multitasking using
>> continuations almost guarantee a repeated back-and-forth through
>> dynamic-wind.
>>
>> I strongly suspect Scheme's continuations are more trouble th
ting coroutines and cooperative multitasking using
> continuations almost guarantee a repeated back-and-forth through
> dynamic-wind.
>
> I strongly suspect Scheme's continuations are more trouble than they
> are worth.
I disagree with that. On the first point, you know that a
dynamic
Marko Rauhamaa writes:
> Amirouche Boubekki :
>
>> I consider dynamic-wind an advanced concept not required for usual
>> hacking.
>
> Hm. Python's try/finally has several uses in virtually every program.
>
> Trouble is, Scheme's continuations make it impos
Amirouche Boubekki :
> I consider dynamic-wind an advanced concept not required for usual
> hacking.
Hm. Python's try/finally has several uses in virtually every program.
Trouble is, Scheme's continuations make it impossible to know when
something is really final. In fa
Héllo all!
On Wed, Jul 5, 2017 at 8:14 AM Catonano wrote:
> My point is that the manual does not a good job of _introducing_ people to
> the concept of dynamic wind
>
> Especially people wo have not clear in mind a complete map of the use cases
> with relative possible solutions.
Catonano writes:
> Chris,
>
> thank you for your remarks.
>
> Yo're right that I was being caught up by continuations AND that I was
> probably missing the generality of the concept of dynamic wind
>
> And yet, I still want to clarify my point
>
> My point is n
Chris,
thank you for your remarks.
Yo're right that I was being caught up by continuations AND that I was
probably missing the generality of the concept of dynamic wind
And yet, I still want to clarify my point
My point is not that the manual is incomplete or inaccurate
My point is tha
> > (enter-context)
> > (action)
> > (leave-context))
> >
> > you simply change it to
> >
> > (define (within-context action)
> > (dynamic-wind
> > (lambda () (enter-context))
> > action
> > (lambda () (leave-context
Thank you !!
ed. I don't understand it
>>
>> How is it supposed to be used ?
>>
>>
> It's very simple (at least from the point of view of a user)
> When it is tempting to write something like
>
> (define (within-context action)
> (enter-context)
> (actio
very simple (at least from the point of view of a user)
When it is tempting to write something like
(define (within-context action)
(enter-context)
(action)
(leave-context))
you simply change it to
(define (within-context action)
(dynamic-wind
(lambda () (enter-context))
action
(freexl-open "path/to/my/xls-file.xls" handler-ptr)
(freexl-do-something handler-ptr)
(freexl-do-something-more handler-ptr))
(freexl-close handler-ptr)
Do I need dynamic-wind at all ?
Hi,
"Neil Jerram" <[EMAIL PROTECTED]> writes:
> Could you make that change?
Yes, done:
http://git.savannah.gnu.org/gitweb/?p=guile.git;a=commitdiff;h=7635043239e9ac2786fec54df3eff73c7f213518
Thanks!
Ludo'.
2008/11/23 Ludovic Courtès <[EMAIL PROTECTED]>:
>
> Exactly, thanks! Now, I was actually using SRFI-34's
> `with-exception-handler', which I expected to behave like
> `with-throw-handler'. Should we change `with-exception-handler' to use
> `with-throw-handler' instead of `lazy-catch'?
Yes, I thi
Hi Neil,
"Neil Jerram" <[EMAIL PROTECTED]> writes:
> This is as expected. Note that there is nothing like dynamic-wind
> inside fluid-set! Did you perhaps mean with-fluids instead? If you
> used with-fluids, I would expect the same behaviour as you've
> descr
> (lazy-catch #t
> (lambda ()
>(fluid-set! fl 'inside)
>(throw 'foobar))
> (lambda (key . args)
>(format #t "fluid = ~A~%" (fluid-ref fl))
>(exit 1)))
>
> =>
(lazy-catch #t
(lambda ()
(parameterize ((fl 'inside))
(throw 'foobar)))
(lambda (key . args)
(format #t "fluid = ~A~%" (fl))
(exit 1)))
=> PRINTS: fluid = outside
This comes fro
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