the boxed verbs are limited. I mentioned that I can store as ARs instead. But
extracting 1 verb is a verb that can be applied:
(1 {:: (('X' Cloak ("0)(<@) )) 3 4 ) 2 3 4
6 7 8
Because "X cloaked" is applied "0, the results are assembled based on the shape
of y (i.3 3 in original example)
> What 'major need' is my proposal not addressing? It seems to me that it
allows you to return non-nouns (as ARs) and execute them (using ".).
ARs are nouns. We already know how to produce ARs. Modifiers are first class,
and more powerful than verbs, because they can produce non-nouns. A path to
channel verb results (nouns) to modifiers (n: as I've proposed it) is a path to
leverage the power of modifiers. Can do so without changing verbs or
modifiers. It's a big improvement. Or just let Cloak keep "working".
The original thread for (A n) request was about attributes possibly annotating
a noun. This post uses an (A APPLY n) solution to access and return such
decorated nouns:
http://www.jsoftware.com/pipermail/programming/2023-January/061916.html
Closures is a new topic. This is typically considered binding function and
noun, where access can change the function or noun.
The basic version is Modifiers are useful. That a verb could access its x and
y arguments to produce a result before feeding that to a modifier in a single
verb phrase is useful. It is still mechanics of verbs returning nouns.
On Tuesday, January 17, 2023 at 10:27:18 p.m. EST, Henry Rich
<henryhr...@gmail.com> wrote:
Your ('X' Cloak(<@)("0) i.3 3) is interesting. It seems to display as
an array of boxed verbs. What would be the result if you opened that?
Can you apply all the verbs on an argument? What is the verb rank of
the boxed array, especially if the contents are verbs with different
ranks? How are the results assembled?
What 'major need' is my proposal not addressing? It seems to me that it
allows you to return non-nouns (as ARs) and execute them (using ".).
Please answer these questions without reverting to your
eval/isNoun/Cloak etc. How your noncompliant methods work is immaterial
to this discussion (though they are interesting); I want to learn about
deficiencies in my proposal.
I appreciate that we are all trying to make J better. I just think that
having verbs return non-nouns is not the way to do it.
Henry Rich
On 1/17/2023 10:10 PM, 'Pascal Jasmin' via Programming wrote:
> More ways to generate ARs doesn't hurt, but its not verbs returning
> non-nouns, or a path (n:) to obtain non-nouns from a verb phrase, so then the
> proposal is not meeting a major need.
>
> repeating definitions,
>
> eval_z_ =: 1 : 'if. 2 ~: 3!:0 m do. m else. a: 1 : m end.' NB.1 : ' a: 1 : m'
>
> isNoun_z_ =: (0 = 4!:0 ( :: 0:))@:<
>
> aar =: 1 : 'if. isNoun ''u'' do. q =. m eval else. q =. u end. 5!:1 < ''q'' '
>
> Cloak=: aar(0:`)(,^:)
>
> X=: 1 : 'm&+'
>
> to answer your hypothetical DV question, it is actually possible to box verbs.
>
> 'X' Cloak(<@)("0) i.3 3
>
> ┌────┬────┬───┐
>
> │00&+│01&+│2&+│
>
> ├────┼────┼───┤
>
> │3&+ │4&+ │5&+│
>
> ├────┼────┼───┤
>
> │6&+ │7&+ │8&+│
>
> └────┴────┴───┘
>
> ('x3 x4' =. ('X' Cloak(<@)("0) 3 4))
>
> x3
>
> 3&+
>
> x3 2
>
> 5
>
>
> using boxed verbs does require fishing them out, and an ar adverb (('ar' oa)
> instead of (<@) makes them more "flexible". Parser and display seem
> resilient/solid to these shenanigans.
>
>
>
> On Tuesday, January 17, 2023 at 06:53:15 p.m. EST, Henry Rich
> <henryhr...@gmail.com> wrote:
>
>
>
>
>
> Verbs are first-class in J, in that they can be passed as ARs or by name
> and invoked in an explicit verb. Nothing more is needed.
>
> If a programmer is restricted to the tacit language (why? - I dunno)
> verbs cannot be first-class. That seems to matter to some people. I
> was trying to give them something. I don't love the proposal either,
> but it seems pretty harmless.
>
> Any dangerous verb that attempts to return a non-noun is going to be
> crash-prone. What would DV"0 (6 6)$'+' mean? Its result is what type?
> what shape?
>
> I haven't followed the proposals closely. All I know is that having a
> verb return a non-noun is going to create havoc inside JE.
>
> Henry Rich
>
> On 1/17/2023 6:42 PM, Elijah Stone wrote:
>> I don't love the proposal, as I think a conception of verbs as first
>> class should involve _less_ hackery with representations, not more.
>> But I don't feel that strongly either way.
>>
>> More fruitful, IMO, would be to work out how to add closures, as I
>> think there is a more urgent need for that (u./v. is a band-aid).
>> Perhaps taking inspiration from kernel (but skipping the mutation!).
>>
>> On Mon, 16 Jan 2023, Henry Rich wrote:
>>
>>> I have never understood the zeal for having verbs return verbs, but
>>> it must be real if some are willing to use dangerous backdoor hacks
>>> into JE to achieve it. ARs make it possible to pass verbs around, but
>>> executing them requires dropping into explicit code. To remedy this,
>>> I offer a proposal, backward compatible with older J:
>>>
>>> 1. (". y) and Apply (x 128!:2 y) to be modified so that if the result
>>> of execution is not a noun, it is replaced by its AR (instead of ''
>>> as previously).
>>>
>>> 2. (". y) and Apply to be modified so that if y (for ".) or x (for
>>> Apply) is boxed, the sentence is executed as usual except that each
>>> box is converted using (box 5!:0) before being put onto the execution
>>> stack.
>>>
>>> The idea is that you can execute (".
>>> expr-producing-AR,exp-producing-AR,...) without having to get any
>>> modifiers involved.
>>>
>>> Sentence execution can produce ARs, and can take ARs created by verbs
>>> to represent verbs and modifiers. That sounds pretty classy to me,
>>> but I don't know whether it's first-class.
>>>
>>> Henry Rich
>>>
>>>
>>>
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