Source =. 'a';'bcd';'e';'g' Target =. 'e';'a';'bcd';'f' getIndex =: i.~ NB. not e. shouldReturn =. 1 2 0 4 NB. 'not found' for i. is #x assert (Source getIndex Target)-:shouldReturn NB. -: not =
Henry Rich On 4/23/2012 7:13 AM, Joe Bohart wrote: > Hi J'ers, > > I'm trying to write a verb that will > match the items in Source with Target > and return the index of items in Target > such that they are in the same order as > Source with nulls (or the J way of handling nulls) > if no match is found. > > This is what i have (and it's wrong): > > Source =. 'a';'bcd';'e';'g' > Target =. 'e';'a';'bcd';'f' > getIndex =: e. > shouldReturn =. 1 2 0 null > assert (Source getIndex Target)=shouldReturn > > In the forums I've found solution candidates,but > haven't been able to apply them and am a bit lost with: > I.@:E. and ;: > > The concept of expressing null or missing data in J I haven't > found much info on. Where can i find more information on nulls. > > Much Thanks -Joe > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm