Now that I think of it, x m&v y is equivalent to x (m&v @ ] ^: [) y
so there is never going to be a case where dyadic m&v is necessary. The
question is how valuable the uses mentioned are. I know I have lost a
lot of time over the years by mistaken execution of dyadic m&v, and a
domain error would have served me better.
Henry Rich
On 8/17/2020 10:57 AM, 'Pascal Jasmin' via Programming wrote:
Tetration (I think it is called) is an impressive display of dyadic (m&)
You are allowed to keep adding (&m) bindings.
As a hybrid depth/breadth first (do depth 10 times in a breadth way), then
10 x&search^:(until)^:_ y
lets you make that chunk size a verb parameter.
With that said, there is surely a way to box x, and extract items from it on the v side
of ^:, but then you need to include a 1 result in the relevant x position and set a
maximum possible "exponentiation/tetration" level.
While I certainly admit that in the life of a J programmer, you will more often
accidentally call a bound (&) verb dyadically on accident rather than on
purpose, which often results in infinitish loop hang/delays, it hasn't happened to
me in a while, so I'm somehow hopeful that it this construct could still be more
useful than my future accidents probabilities.
On Monday, August 17, 2020, 10:21:05 a.m. EDT, Henry Rich
<henryhr...@gmail.com> wrote:
On the current implementation it is much preferable to use
bitmask operator@]^:["0 operand
rather than
bitmask 0&(] operator)"0 operand
They both execute at low rank, but the second version reinterprets the
internal form ( 0&(] operator)^:bitmask ) for each atom.
I have yet to find an application where (x m&v y) is needed. Does anyone
have one? In the example above, the 0& could be any value and is used
only as a way of getting the power function.
Henry Rich
On 8/17/2020 9:30 AM, David Lambert wrote:
Yes, thank you Roger for this explanation of dyadic & which i've recently
been thinking about how to incorporate into my j programming.
|Date: Sun, 16 Aug 2020 21:00:42 +0000 (UTC)
|From: "'Pascal Jasmin' via Programming" <programm...@jsoftware.com>
|To: "programm...@jsoftware.com" <programm...@jsoftware.com>
|Subject: Re: [Jprogramming] conditional application defined by bitmask
|Message-ID: <316224114.2834748.1597611642...@mail.yahoo.com>
|Content-Type: text/plain; charset=UTF-8
|
|Roger's solution includes an intermediate-advanced J concept I knew about,
and an advanced realization I did not previously realize/know about.
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