Raul, As usual, instant help: to my nightly prayers I will add the hope that I never take you for granted.
Fold! Yes. Of course. I’ve read about fold but never tried it…but when I put in one of the examples I got a nonce error z =: u F:. v y not found: /private/var/mobile/Containers/Data/Application/8C177CA5-F2BD-49C0-AE12-95A58065F82F/Documents/j/addons/dev/fold/foldr.ijs |nonce error | z=:u F:.v y …which confuses me since the documentation states that 9.01 has it (though the execution of u and v was reversed in 9.02). JVERSION Engine: j903/j64/iOS beta-k: GPL3/2021-10-15T01:07:05 Platform: iOS/iPadOS Version: 901.1 49 Installer: App Store Contact: www.jsoftware.com Looks like it might be an iPad quirk. To your point about restructuring the design—hmm. Yes. Once I know that the first n coordinates fail f, they’ll never again succeed, so I can safely discard them from consideration in subsequent passes (of which there may be many). That all by itself may represent a significant savings. There are probably other optimizations but first…I need a solution that works slowly. Thanks again. Ed Sent from my iPad > On Oct 21, 2022, at 11:29 AM, Raul Miller <rauldmil...@gmail.com> wrote: > > This sounds like a terminated fold. > > Something like > https://wiki.jsoftware.com/wiki/Vocabulary/fcap#How_should_I_define_u_and_v.3F > ... maybe 0 ]F..(_2 Z: f@[) coords > > (That said, you probably want to restructure your description a bit so > that you can get a useful result from all of this work.) > > I hope this helps, > > -- > Raul > > >> On Fri, Oct 21, 2022 at 12:19 PM Ed Gottsman >> <edward.j.gotts...@gmail.com> wrote: >> >> Hi. I’m blanking on something basic and research isn’t helping. When the >> blindingly obvious solution is revealed I will blame a combination of sleep >> deprivation and senescence. >> >> I’ve got a long list of coordinates ordered by desirability. I want to >> invoke f (a custom script) with each coordinate in turn. f may return 0 >> (failure), in which case I want to invoke it again with the next coordinate. >> When f (eventually) returns 1, I want to terminate—the remainder of the >> coordinates should not be processed. (Note that the very first invocation >> of f may return 1.) >> >> This *almost* feels like ^: in its Do While form. Almost. It also feels >> like SCs around list operations (though they seem to be limited to >> primitives). >> >> Help. >> >> Many thanks. >> >> Ed >> >> Sent from my iPad >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm