I was thinking about the usefulness of a monadic ↓ in terms of the new regexp feature. In the current version, when using subexpressions, the return value is always 1+the number of subexpressions, where the first one is always the full matched string. Monadic ↓ would be a neat way of dropping that part.
In any case, my point is that monadic ↓ should do something useful. I guess split is one such useful thing. In GNU APL, I'd use ⊂⍤1 to achieve Split. Is that the most efficient way? Regards, Elias On 9 October 2017 at 16:58, Jay Foad <jay.f...@gmail.com> wrote: > On 9 October 2017 at 04:56, Elias Mårtenson <loke...@gmail.com> wrote: > >> Currently, monadic ↑ acts as if it was called dyadically with 1 as its >> left argument, >> > > That's not quite true: > > ⍴⍴1↑'ABC' > 1 > ⍴⍴↑'ABC' > 0 > > while monadic ↓ raises a VALENCE ERROR. In almost every single case where >> I have used ↓, it has been in the form 1↓X. Is there a reason why the >> monadic form is not allowed? >> > > FYI in Dyalog APL monadic ↓ is Split: > > ↓3 3⍴⎕A > ┌───┬───┬───┐ > │ABC│DEF│GHI│ > └───┴───┴───┘ > > I believe this came from STSC's NARS. > > Jay. >
