f =: (+^:10)&0 f 5 50
the f below, uses x as the "original y", and y is an additional number to be added to (set to 0 here to be equivalent to no parameter). in ^:, the x parameter to the resulting verb is a constant. ----- Original Message ----- From: Jon Hough <[email protected]> To: "[email protected]" <[email protected]> Cc: Sent: Sunday, August 2, 2015 12:06 PM Subject: Re: [Jprogramming] Understanding ^: Thanks, yes my attempt doesn't work, and it was a bit silly. I was just trying to give the simplest possible example of my problem. I think my example hasn't shown the issue I'm talking about. I want to do some iteration on y, where each step of the iteration has access to the original y value. I'm not sure how to do this, because it seems that everything to the left of ^: has no access to the initial value. > Date: Sun, 2 Aug 2015 15:55:14 +0000 > From: [email protected] > To: [email protected] > Subject: Re: [Jprogramming] Understanding ^: > > first you are using + monadially here. > > A conjunction (most of them) becomes a verb after it has 2 arguments bound to > it. So, > > f =: +^:10 > > is a dyadic (or monadic verb, but monadic + is not that interesting) > > 5 (+^:10) 0 > 50 > > 5 (+^:10) 2 > 52 > > > A way to double 10 times, that looks a bit similar but is a monadic adverb > > 10 (+:^:) 2 > 2048 > > > A dyadic adverb needs 2 parameters on the right > > f =. +^: > > 5 (10 f) 2 > 52 > > > > > ----- Original Message ----- > From: Jon Hough <[email protected]> > To: "[email protected]" <[email protected]> > Cc: > Sent: Sunday, August 2, 2015 11:26 AM > Subject: [Jprogramming] Understanding ^: > > I'm attempting some functions that use verb power (^:) , but I'm a little > lost when it comes to the concept of what is getting iterated. > For example, in pseudo code: > function f(y){ > a = y; //cache initial value > > counter = 10; > while(counter-->0){ > y = y + a; > } > return y;} > In the above code, y was initially cached for later use. Trying this in tacit > J I did: > f =: +]^:10 > which completely gives the wrong result. Obviosuly the above function is not > interesting, and I'm attempting more interesting things, but the principle is > the same, how can I cache the initial value for use in each iteration when > using ^:? Do I need to use explicit verbs instead? > Thanks, > Jon > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
