On Wed, Oct 21, 2009 at 1:04 PM, <[email protected]> wrote: > ... > > Some notes: > ... > + I would avoid tricks along the lines of +/@:, etc. Let the user decide > what cells he wants to test for "definedness" (eg atoms, items, total array), > and let him use the normal J mechanisms to do this (ie rank). The definiton > of "undefined" can be domain-dependent (witness Perl's 'zero'), so permit > that flexibility (eg by making your convenience predicate infinite rank). > Incidentally, this saves you both more design decisions and coding work. >
Dan, Between my earlier messages and seeing your reply it occurred to me that a big flaw with the +/@:, portion of my verb is that it drives it away from being convenient for use on items, and instead ties it to scalar presumptions. It's a mistake I often make when starting to draw on something from another language. Yes, the remedy for that mistake is to let the normal J mechanisms apply. Tracy ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
