Ah of course, thanks! On Thu, Oct 07, 2021 at 05:52:55PM -0700, Sorawee Porncharoenwase wrote: > Typo: with-handlers* > > On Thu, Oct 7, 2021 at 5:52 PM Sorawee Porncharoenwase < > [email protected]> wrote: > > > I think you want with-handler*? According to the docs: > > > > with-handlers: > > > > Before any predicate or handler procedure is invoked, the continuation of > > the entire with-handlers > > <https://docs.racket-lang.org/reference/exns.html#%28form._%28%28lib._racket%2Fprivate%2Fmore-scheme..rkt%29._with-handlers%29%29> > > expression is restored, but also parameterize-break > > <https://docs.racket-lang.org/reference/breakhandler.html#%28form._%28%28lib._racket%2Fprivate%2Fmore-scheme..rkt%29._parameterize-break%29%29>ed > > to disable breaks. Thus, breaks are disabled by default during the > > predicate and handler procedures (see Breaks > > <https://docs.racket-lang.org/reference/breakhandler.html>), and the > > exception handler is the one from the continuation of the with-handlers > > <https://docs.racket-lang.org/reference/exns.html#%28form._%28%28lib._racket%2Fprivate%2Fmore-scheme..rkt%29._with-handlers%29%29> > > expression. > > > > with-handler* > > > > Like with-handlers > > <https://docs.racket-lang.org/reference/exns.html#%28form._%28%28lib._racket%2Fprivate%2Fmore-scheme..rkt%29._with-handlers%29%29>, > > but if a handler-expr procedure is called, breaks are not explicitly > > disabled, and the handler call is in tail position with respect to the > > with-handlers* > > <https://docs.racket-lang.org/reference/exns.html#%28form._%28%28lib._racket%2Fprivate%2Fmore-scheme..rkt%29._with-handlers%2A%29%29> > > form. > > > > On Thu, Oct 7, 2021 at 5:36 PM 'William J. Bowman' via Racket Users < > > [email protected]> wrote: > > > >> I have a little model of a server below. The server handles all > >> exceptions, and restarts itself after some errors. It also handles break?, > >> to actually exit when requested. > >> > >> While this server is running, if I press Ctrl+C before `(error 'foo)` is > >> handled, the server exits correctly with 120. However, if I press Ctrl+C > >> after `(error 'foo)` is handled, the `exn:break?` handler is never called, > >> the server no longer responds to `Ctrl+C`, and (in this example) it > >> eventually exits with status `1`. > >> > >> I cannot figure out why. As far as I can tell, this should always handle > >> `Ctrl+C` by exiting with 120. > >> > >> > #lang racket/base > >> > > >> > (let loop ([n 0]) > >> > (with-handlers ([exn:break? (lambda _ (exit 120))] > >> > [void > >> > (lambda (exn) > >> > (printf "handled error: ~a~n" (exn-message exn)) > >> > (loop (add1 n)))]) > >> > (displayln n) > >> > (sleep 1) > >> > (cond > >> > [(zero? n) (error 'foo)] > >> > [(= n 5) (exit 1)]) > >> > (loop (add1 n)))) > >> > >> -- > >> William J. Bowman > >> > >> -- > >> You received this message because you are subscribed to the Google Groups > >> "Racket Users" group. > >> To unsubscribe from this group and stop receiving emails from it, send an > >> email to [email protected]. > >> To view this discussion on the web visit > >> https://groups.google.com/d/msgid/racket-users/YV%2BSWNpldfOB5tA3%40williamjbowman.com > >> . > >> > >
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