That ^:L. is a good idea, one that I would have used a few times if I'd thought of it.
FYI: L. by itself is usually a mistake. It recurs through all boxing to the bitter end. Better to use (0 < L.) which allows early exit. Henry Rich On Sat, Dec 16, 2023, 7:36 PM Raul Miller <rauldmil...@gmail.com> wrote: > I've also used U^:L.L:1 when dealing with that kind of data structure > where I only wanted to act on the part that's deeply nested. > > !L:0^:L.L:1 (<0 1 2),<2 4;3 5 7 > ┌─────┬─────────────────┐ > │0 1 2│┌────┬──────────┐│ > │ ││2 24│6 120 5040││ > │ │└────┴──────────┘│ > └─────┴─────────────────┘ > > You can see a more interesting example in the implementation of disp > at > https://code.jsoftware.com/wiki/Essays/RegularExpressions/NondeterministicFiniteAutomata > > FYI, > > -- > Raul > > On Sat, Dec 16, 2023 at 7:18 PM 'Nollaig MacKenzie' via General > <gene...@jsoftware.com> wrote: > > > > I like L: a lot. You can do neat things: > > > > ! L: 0 (<0 1 2),<2 4;3 5 7 > > ┌─────┬─────────────────┐ > > │1 1 2│┌────┬──────────┐│ > > │ ││2 24│6 120 5040││ > > │ │└────┴──────────┘│ > > └─────┴─────────────────┘ > > > > > > > On Dec 16, 2023, at 09:09, Henry Rich <henryhr...@gmail.com> wrote: > > > > > > 'prefix' ,L:0 names > > > > > > Untested. > > > > > > Henry Rich > > > > > > > ---------------------------------------------------------------------- > > 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
