Hmm...
Two challenges here.
One would be finding appropriate delimiters - for example, we might
use (. ). and (: ): where K uses {} and [], and =: where K uses :
The other would be defining suitable parsing rules. This turns out to
be a non-trivial issue (depending on how much of K's grammar we would
want to incorporate and how much of J's explicit definitions we would
want to incorporate).
That said, if you (or someone else) wanted to extend the parsing table
at http://www.jsoftware.com/help/dictionary/dicte.htm to achieve this,
I think we all might be interested in the result.
(It's tempting to say "it's just another kind of string literal that
gets handed of to an independent parser" - but if you go that route
you have forbidden nesting these definitions, and it's probably better
to stick with the existing approach instead.)
Thanks,
--
Raul
On Tue, Nov 21, 2017 at 1:56 PM, Alex Shroyer <[email protected]> wrote:
> @AndrewD: I've been using J casually for about 2 years, and consider myself
> an "intermediate beginner". I also use Python, and my impression is that
> Python makes it easy to see what the author *wanted* the program to do, but
> J makes it easier to see what the program *actually does*.
>
> However, one frustration I still have is regarding explicit definitions.
> IMO they should be replaced with something more like what the K language
> provides, namely first-class, lexically-scoped functions:
>
> add: {x+y}
> scan: {x\y}
> scan [add; 2 3 4]
> 2 5 9
>
> Perhaps J's syntax could be extended someday, to recognize this type of
> function in an explicit definition, for example:
>
> add =: dyad def 'x+y'
> scan =: HOF def 'x\y' NB. in this scheme, HOF stands for 'higher-order
> function' and tells interpreter to not evaluate x or y until both arguments
> are bound
> add scan 2 3 4
> 2 5 9
>
> There are a few other things I'd like J to take from K, but that's the big
> one.
>
> On Mon, Nov 20, 2017 at 11:16 AM, chris burke <[email protected]> wrote:
>
>> Dear All
>>
>> My attempt to move this thread over to programming failed, but please note
>> for future use that discussions like this on the language are much better
>> addressed to the programming forum. Not least, they will then reach all J
>> forum readers, not just those subscribed to general. See http://code.
>> jsoftware.com/wiki/System/Forums .
>>
>> Thanks.
>>
>> Chris
>> ----------------------------------------------------------------------
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>>
> ----------------------------------------------------------------------
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