Typo: with-handlers* On Thu, Oct 7, 2021 at 5:52 PM Sorawee Porncharoenwase < sorawee.pw...@gmail.com> 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 < > racket-users@googlegroups.com> 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 racket-users+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/racket-users/YV%2BSWNpldfOB5tA3%40williamjbowman.com >> . >> > -- 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 racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/CADcuegv2uWs_2KnFw%2ByD2OzmOVBi5tkktyh8Aour1E5xTh-RKw%40mail.gmail.com.
