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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