Generally speaking, in computing contexts, "powerful" is orthogonal to "useful".
Which might be related to why explicit definitions are looked down on,
by some in the J community -- It seems that they're "too powerful".
But if the problem is that explicit definitions are insufficiently
constrained, why should we want to burden tacit definitions with this
defect?
--
Raul
On Wed, Jan 18, 2023 at 12:40 AM 'Pascal Jasmin' via Programming
<programm...@jsoftware.com> wrote:
>
> 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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