I often get tripped up with different trailing shapes when using i. with char arrays. I must not be the only one[1]
Does this look like a suitable utility to deal with it or is there a more common way? Y1=:0&{:: Y2=:1&{:: idotfill =. (( ( (_,]) {. Y1@[) i. ((_,]) {. Y2@[) ) {:@$@Y2 >. {:@$@Y1) f. idotfill (>'SF';'SY';'PK ');(>'SF';'SY') 0 1 compare with NB. different trailing shape (>'SF';'SY';'PK ') i. (>'SF';'SY') 3 3 NB. remove the trailing space on PK (>'SF';'SY';'PK') i. (>'SF';'SY') 0 1 [1] - "y must match the entire row of x (including any trailing fill letters) for (i.) to find it. Otherwise (i.) returns (#x) (signifying "not found"), concealing your error." http://code.jsoftware.com/wiki/Vocabulary/idot#dyadic ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm