Ric gave the example I thought of (change 'first item' to 'last item' in the example).
Generally you need @ when your verb has to have rank other than _ . Try this: create a verb that produces a sequence of index vectors for the atome of its input, by which I mean v 3 5 2 0 1 2 0 1 2 3 4 0 1 Using @ you have v =: ; @: (<@i."0) I can do it without @ but I don't think I'd want to. Henry Rich > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Alex Rufon > Sent: Thursday, September 11, 2008 4:10 AM > To: General forum > Subject: [Jgeneral] Verb Sequences - u@:v and [EMAIL PROTECTED] > > Hi. > > I'm at Chapter 12 of J for C Programmers and Henry was explaining verb > sequences. > > You see, I have never ever used @: or @ in my years of use of > J so this > is a bit confusing for me. > > Like in the example on page 111 where it defines: > ]a=: 1 2 3; 4 5; 6 7 8 > +-----+---+-----+ > |1 2 3|4 5|6 7 8| > +-----+---+-----+ > > The requirement was remove the first box and just get the > first items of > the succeeding boxes. The solution that was provided was: > }.@:({.@>) a > 4 6 > > Since I've don't use "Verb Sequences", my solution was: > }. {. "1 > a > 4 6 > > I tried doing the other samples and I can still come up with solutions > without using the @ and @: symbols. > > So I am wondering if anybody has good examples where I would > absolutely > need to use verb sequencing so I can compromise with myself when to > properly use the symbols. > > Thanks. > > r/alex > ---------------------------------------------------------------------- > For information about J forums see > http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
