Even worse, the following routine is faster. And since the following routine is also disgusting code, I don't want to put it into the article.
:firstnz2(list)
:intDiv(inString(string(list=0*list),"f")+3,5)
This routine works by first creating a list of the same size that's entirely 0, then comparing it to the original list (getting a list of true and false), turning the result into a string, searching for the letter "f" in the string, and converting the index into an index for the list by division. Ugh!
Edit: a slightly slower but more intuitive method:
:firstnz3(list)
:Func
:Local i
:For i,1,dim(list)
: If list[1]≠0
: Return i
:rotate(list)→list
:EndFor
:0
:EndFunc
Edit 2: my fastest routine so far (still quite ugly, but less so) is
:firstnz4(list)
:mod(1+sum(intDiv(1,1+cumSum(abs(list)))),dim(list)+1)
