On Sat, Jul 24, 2010 at 10:16 PM, Roger Hui <[email protected]> wrote: > I have been asked by some APL colleagues about > index origin 0 in J. The question is, does the choice > of a fixed value of 0 for index origin a hindrance to > your work? The question is specifically addressed > to "ordinary domain experts", people with no > software engineering in their background and are not > professional mathematicians. > > In case you did not know, in APL there is a choice > known as the index origin, controlled by the variable > quad-io, of counting from 1 instead of from 0, affecting > the left argument of { and the result of i. , among other things. > I will say no more than this to avoid biasing your answers. >
I am okay with index origin 0. I see the reasons, like Dijkstra did[0], but some of my friends, whom I would call ordinary domain experts without much experience in programming, felt uncomfortable about it, at least in the beginning. However, when I tell them the index means "interval points"(like a cursor), they made less mistakes. You may see some debates on this[1]. [0] E.W. Dijkstra Archive: Why numbering should start at zero (EWD 831) http://userweb.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/EWD831.html [1] Why numbering should start at 0 | Lambda the Ultimate http://lambda-the-ultimate.org/node/1950 > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
