Running dissect on a line, and then clicking around in the display,
might help visualization.
Henry Rich
On 8/2/2015 12:12 PM, 'Pascal Jasmin' via Programming wrote:
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
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