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 >> . >> > -- 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/CADcuegv2uWs_2KnFw%2ByD2OzmOVBi5tkktyh8Aour1E5xTh-RKw%40mail.gmail.com.
