This is what I had in mind:
(g =. '>@{&paths'&apply f.) NB. instead of (g=. >@{&paths))
'>@{&paths'&(128!:2)
paths=. 2 ([: (|. each) (;~ 0$0) , (<\@:+ i.)) 7
g 4
4 3 2
g 3 2 $ 2 4 1 5 0
2 0 0 0
4 3 2 0
0 0 0 0
5 4 3 2
0 0 0 0
2 0 0 0
g 8
8 7 6 5 4 3 2
paths=. 3 ([: (|. each) (;~ 0$0) , (<\@:+ i.)) 8
g 4
5 4 3
g 3 2 $ 2 4 1 5 0
3 0 0 0
5 4 3 0
0 0 0 0
6 5 4 3
0 0 0 0
3 0 0 0
g 8
9 8 7 6 5 4 3
This approach is lazy friendly, namely, it is easy to implement and it
can also deal easily with multiple nouns, verbs, adverbs and
conjunctions (to introduce, presumably wanted, side effects).
______________________________________________________________________
On Mon, Jul 23, 2012 at 8:34 AM, Pepe Quintana
<[email protected]> wrote:
> One can also apply the linear representation of a (monadic) verb at run-time
> using (&apply). Self-modifying verbs remind me sport motorcycles:
> dangerously powerful and lots of fun!
>
______________________________________________________________________
On Sun, Jul 29, 2012 at 11:59 PM, Ian Shannon
<[email protected]> wrote:
> There is another solution.
>
> Make your noun into a verb as in:
>
>
>
> NB. just a few helpers, could be defined later.
> pathA =: [: (|. each) (;~ 0$0) , (<\@:+ i.) NB. calculation of the data
> pathB =: <\ i. NB. Either monadic or dyadic hook, possible
> pathC =: (2 pathA 7)"_ NB. Set the noun into a verb
>
> NB. Define your verb, this definition doesn't change
> NB. At this point "paths" must be either undefined or a verb!
> g =. >@{ paths NB. This is now a hook
>
> NB. we specify what the paths are that verb g is to use.
> paths =: 2 pathA 7: NB. This constant verb (fork) corresponds
> NB. to your first example data
> g 4
>
> g 3 2 $ 2 4 1 5 0
>
> g 8
>
> paths =: pathC NB. This also corresponds
> NB. to your first example data
> g 4
>
> g 3 2 $ 2 4 1 5 0
>
> g 8
>
> paths =: 3 pathB 16"_ NB. Another constant verb (also a fork)
> g 4
>
> g 3 2 $ 2 4 1 5 0
>
> g 8
>
> paths =: _3 pathB 16"_ NB. Another constant verb (also a fork)
> g 4
>
> g 3 2 $ 2 4 1 5 0
>
> g 8 NB. gives an error!
>
>
>
>
>
> Ian
> Ian Shannon
> Landscape Modelling & Decision Support
> Scientific Services
> Office of Environment and Heritage
> Department of Premier and Cabinet
> PO Box A290
> Sydney South
> NSW 1232
> T: +61 2 99 955 490
> E: [email protected]
> -----Original Message-----
> On Jul 22, 2012 1:32 PM, "David Vaughan" <[email protected]> wrote:
>> I have a noun called paths, whose value changes at various points, and a
>> verb g that uses paths. The problem is, it only works for the initial value
>> of paths.
>>
>> paths =: \:~&.> (;~ 0$0) , <\ 2+i.7
>> paths
>>
>>
>> g =. >@{&paths
>> g
>> @{&((0$0);(0$0);(,2);3 2;4 3 2;5 4 3 2;6 5 4 3 2;7 6 5 4 3 2;8 7 6 5 4 3 2)
>>
>> So now when paths changes, g becomes useless.
>>
>> My question is how can I get g to always check the value of paths when it
>> is executed? And more generally, how can the name of a noun rather than the
>> value of the noun be used in a verb?
>>
>> Many thanks.
> ----------------------------------------------------------------------------------------------------------------------------------------------------------------------
> This email is intended for the addressee(s) named and may contain
> confidential and/or privileged information.
> If you are not the intended recipient, please notify the sender and then
> delete it immediately.
> Any views expressed in this email are those of the individual sender except
> where the sender expressly and with authority states them to be the views of
> the Office of Environment and Heritage, NSW Department of Premier and Cabinet.
>
> PLEASE CONSIDER THE ENVIRONMENT BEFORE PRINTING THIS EMAIL
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
