([: +/ *:) 1 2 3 4 5 55 cap=: [: (cap +/ *:) 1 2 3 4 5 55 9!:14 '' j601/2006-11-10/14:25
----- Original Message ----- From: "Mark D. Niemiec" <[EMAIL PROTECTED]> Date: Monday, December 24, 2007 23:56 Subject: Re: [Jgeneral] Regrets To: [email protected] > Dan Bron <[EMAIL PROTECTED]> wrote: > > I don't think [: is considered a design > mistake. At least, I don't see > > it that way. Certainly [: g h is a > grammatical anomaly, but it's limited, > > and covered by a single extra sentence in the DoJ (and a > couple of diagrams). For > > that small cost, it has great utility. > > I think it's inelegant, because: > 1) [: behaves semantically unlike any other J verb > (in most cases [:y and x[:y return a domain error > (formerly valence error), > but it doesn't do so as 'f' in 'f g h') > 2) It is impossible to write a user-written version of [: > In particular, if you write: > cap =: [: > fg =: cap f g > You get the 'normal' behavior of [: (domain error) ... ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
