As described in http://keiapl.info/anec/#fork , verbs in J (and APL) are designed so that fixing the left argument makes a sensible monad. However, if a verb (such as % or e.) has a well-established argument order that predates J, then that order is used. In any case, having the reflex (~) adverb takes the sting out of having a "wrong" order.
http://www.jsoftware.com/help/jforc/more_verbs.htm comments on the order of arguments in /: and \: . In these cases the answer is "obvious". With the current order of arguments, /: y \: y x /: y x \: y it is always the right argument which is being graded. ----- Original Message ----- From: Henry Rich <[EMAIL PROTECTED]> Date: Monday, April 16, 2007 9:27 pm Subject: RE: [Jgeneral] "J for C Programmers" - asymmetry / control /data discussed without definition? > "Asymmetric" is standard English, but the others are a bit wooly. > If you're mathematical, think 'noncommutative' for 'asymmetric'. > > a + b is symmetric. > > a i. b is not. > > The idea is, if you were going to be applying this verb a bunch of > times,which operand would be more likely to stay the same? That > is the > 'control information'. So, in > > a i. b > > we guess that the user is more likely going to want to do a bunch > of searches in the same a than he is to do a bunch of searches for the > same b in different a's. So we declare the a to be 'control > information',and we put it on the left. > > It's not rigorous, yet it is important, and there are answers that > many people will agree are correct. > > Henry Rich > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of Terrence Brannon > > Sent: Tuesday, April 17, 2007 12:12 AM > > To: General forum > > Subject: [Jgeneral] "J for C Programmers" - asymmetry / > > control /data discussed without definition? > > > > < quote url = http://www.jsoftware.com/help/jforc/more_verbs.htm > > > if a dyadic verb is asymmetric, you should think of x as > operating on > > y, i. e. x is control information and y is data. > > > > < / quote > > > > > I don't know what "asymmetric", "control information" and "data" > mean.> I'm pretty sure these concepts were not introduced previously. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
