On Mon, Sep 11, 2023 at 2:48 AM 'Skip Cave' via Programming <programm...@jsoftware.com> wrote: > Raul used a 'chain of dyadic verbs' (x F x F x F y) to solve the problem. I > haven't ever tried this, where right-to-left execution is used to feed the > result of one dyadic verb into the next one on the left. It was a bit > confusing until I realized that the rightmost verb 'eats' its left > argument, so that the verb result is passed to the next verb on the left, > instead of the previous verb's left argument. This problem provides a good > example of the use of this feature. I wonder if this linear 'chain of > verbs' could be replaced with the hatco operator (^:)?
You could use (^:) if you could derive the left argument from the right argument. For example, replacing (x) with (#digits y). If that had not been possible, you could have used (/) instead of (^:) but that forces you to box y and the individual x values so that they could exist in a list together (and then you have to unbox them when using them). Alternatively you could have used (]F.:) which behaves similarly but allows an initial value (which would be N1 here) as a left argument rather than being the rightmost element of the array. (But this is a hypothetical general case, because deriving the x argument from the y argument is straightforward here.) FYI, -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
