How about this?:
On Tue, Feb 19, 2019, 9:57 PM Kees-Jochem Wehrmeijer <[email protected]> wrote: > Basically when I call the function throw. So e.g. > > (define mygenerator (generator () > (with-handlers ([exn:fail? (lambda (e) 42)]) > (yield 1) > (yield 2) > (yield 3)))) > > > (mygenerator) > 1 > > (throw mygenerator) > 42 > (define (mygenerator [throw? #f]) (if throw? 42 (begin (yield 1)(yield 2)(yield 3))) > (mygenerator) 1 > (mygenerator 'throw) 42 What sort of thing would you use this technique for? You aren't actually throwing anything, because you trap and discard the exception before returning a value normally. > On Tue, Feb 19, 2019 at 6:20 PM David Storrs <[email protected]> > wrote: > >> Under what circumstances would you want it to throw? When the generator >> runs out, or...? >> >> On Tue, Feb 19, 2019, 3:59 PM Kees-Jochem Wehrmeijer <[email protected]> >> wrote: >> >>> Hi, >>> >>> Python allows to call a .throw() method on a generator. I was wondering >>> if Racket generators have a similar feature. From the docs it doesn't seem >>> to have that. One way I could see around this is to set a parameter and >>> then check for that parameter in the generator and raise an exception based >>> on that. I could imagine writing a macro, e.g. yield-except, that does that >>> check. The disadvantage would be that users would have to remember to use >>> yield-except instead of regular yield in the generator. >>> >>> Are there any other clever workarounds that I'm missing? >>> >>> Thanks, >>> Kees >>> >>> -- >>> 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]. >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- 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]. For more options, visit https://groups.google.com/d/optout.
