Hi all!

See comments below.

Cheers,
Erling

On 2017-09-28 23:45, Louis de Forcrand wrote:
I don't really understand what you wish to add either, Erling.

If you want to use explicit J syntax, you could write an explicit verb.
The main difference between tacit J and explicit J, as I see it, is not the syntax as such but that tacit J lacks mutable state.
I think that is the reason some people use it professionally.
Anonymous verbs are easier to create. This will change if Henry's request is implemented. I have learned some things about how to simplify problem solutions when I messed with tacit J, but yes, if my request does not pass, I guess I will stick to explicit J.

You write:
Particularly to create what you most commonly need, a sequence of
monadic verbs, each acting on the result of the verb to the right.
Well, it is not complicated as such, but for some reason people don't like
the obvious way to do it, which is [: f [: g [: h ]. Then they dive into a
mess of complications. I mean the cap should not be necessary. That simple
right to left execution should be the default, possibly modified with
parenthesis. That tacit and explicit J should have the same basic syntax.
f@:g@:h?
In addition, I disagree with your last two sentences. What's the point of 
having tacit syntax if it's the same as explicit syntax? If you want explicit 
syntax, write an explicit verb; other times tacit syntax is really practical.
In an explicit verb, simple right to left execution *is* the default.
I don't know in what way the tacit syntax could ever be better than what I describe. It is a lot more complex but it is not even shorter. I doubt it is good even for anything it was created to be used for.

In any case I don't really see how the rest of your suggestion differs from 
Henry's (.). verbs, which I like very much by the way.
Yes, well, there is a question if we should move on, work on more than one thread, have non-mutable state, have functions as primary citizens, have anonymous definitions of adverbs and conjunctions, integrate into development environments instead of working at a prompt and very much more, or if we should just keep on doing small changes to a language made for working at a teletype. Tacit J seemed like a step in the right direction because it lacks mutable state. I once thought it was functional programming but as I see it it isn't. Now we have to go back to explicit J because we recognized tacit J is not useful. It means we made very little progress since the teletypes?

Cheers,
Louis

On 28 Sep 2017, at 14:53, Raul Miller <[email protected]> wrote:

Jose's work is impressive, but I try to avoid it because of the extra
complexity it creates when I want to (for example) provide a parameter
in clauses for conjunctions like &. -- the extra complexity can be a
nice mental exercise and maybe even a cure for boredom, but I feel
that I have the right to treat it as unnecessary.

Thanks,

--
Raul


On Thu, Sep 28, 2017 at 8:33 AM, Erling Hellenäs
<[email protected]> wrote:
Hi all !

I am very impressed by Jose's work and I think it is an excellent
illustration to why we need the modification to J I propose.
It is extremely  complicated to do these things which should be simple, as I
see it. Particularly to create what you most commonly need, a sequence of
monadic verbs, each acting on the result of the verb to the right.
Well, it is not complicated as such, but for some reason people don't like
the obvious way to do it, which is [: f [: g [: h ]. Then they dive into a
mess of complications. I mean the cap should not be necessary. That simple
right to left execution should be the default, possibly modified with
parenthesis. That tacit and explicit J should have the same basic syntax. I
tried my ideas of a different tacit J in a test implementation and it was
great.

Cheers,
Erling Hellenäs


On 2017-09-28 05:29, Jose Mario Quintana wrote:

Hi Erling,

You are right, the adverb (At) produces tacit sentences but it is really
an
implementation of Dan's pipeline proposal using strand notation via a
Curried adverb (aka, recurrent adverb and multiple adverb).

However, I have written (tacitly) a tacit Curried adverb (xi) which, using
a lambda-style syntax, produces a tacit verb which in turn, given its
arguments, produces tacit entities.  You might find xi interesting; the
general form is,

t=. [: v0 v1 ... vn '...' xi

The names v0 v1 ... vn should be syntactically verbs (recall, xi is a
Curried adverb) but they can represent nouns, verbs, adverbs, or
conjunctions.  I use undefined names since those are regarded by default
as
verbs (even if xi does not affect in any way the named verbs).  The
literal
'...' represents a quoted J (or more generally a Jx) sentence.

This is how your example can be written using xi,

    erase 'b v'

    [: v '([: b ''<:b++/\b-~-.b'' xi <''\''=v){."0 v' xi <'\\\//\\\//'
\
  \
   \
   /
  /
  \
   \
    \
    /
   /

There is the nuisance of quotes within quotes and the argument must be
boxed; however, this allows, in general, the verb (t) to produce a noun, a
verb, an adverb, or a conjunction and to take multiple boxed nouns, verbs,
adverbs, or conjunctions as its argument.  The following verb (t) acts
directly on a couple of (boxed) verbs and produces a verb,

    t=. [: u v 'u/@:v' xi

    t[:+*:]: NB. Sum of squares
+/@:*:
    t[:+*:]: 1 2 3 4 5
55

    t[:-%:]: NB. Difference of square roots
-/@:%:
    t[:-%:]: 1 2 3 4 5
1.55390522

Note that the Curried higher-order verb (t) is, in effect, acting on two
arguments: [:-%:]: and 1 2 3 4 5; furthermore, t [:-%:]: performs a
partial
application of the verb (t) acting on [:-%:]: .

The following are variations of the verb produced in [0], the verb (t)
acts on a (boxed) conjunction and produces an adverb,

    t=. [: u '(ver adv u)&:train/adv' xi

    ]`{.`{:`{: (t [:(<adv@:)]:)  NB. Use [:(<'@:')sb in J
]@:({.@:({:@:{:))

    ]`{.`{:`{: (t [:(<adv@ )]:)  NB. Use [:(<'@ ')sb in J
]@({.@({:@{:))

    ]`{.`{:`{: (t [:(<adv&:)]:)  NB. Use [:(<'&:')sb in J
]&:({.&:({:&:{:))

These non-compliant features are not provided by the Jx interpreter; they
are, in fact, inherited from the J interpreter, the Jx facilities just
make
them a lot more accessible.  Actually, I have written a version
(admittedly
cumbersome) of xi in J; see [1] for a link to a zip archive and the path
to
a script where xi is defined.

PS.
    erase'u0 u1 u2'
1 1 1
    [: u0 u1 u2 'u0 + u1 + u2' xi 1 ; 2 ; 3
6

    erase'α β γ'
1 1 1
    [: u0 u1 u2 'u0 + u1 + u2' xi [:α β γ]:
α + β + γ

References

[0] [Jprogramming] Gerund composed application
     http://www.jsoftware.com/pipermail/programming/2017-
September/048797.html

[1] J Wicked Toolkit
     http://www.2bestsystems.com/foundation/j/Jx.zip
     \Jx\J\J Wicked Toolkit.ijs

















On Wed, Sep 27, 2017 at 5:10 AM, Erling Hellenäs
<[email protected]>
wrote:

Hi all !

Pascal, I will come back to your post later.

Here is a little compiler written in Jx and compiling, as I understand
it,
tacit code with explicit J syntax into tacit J. I did not test it, I just
read the post.
http://www.jsoftware.com/pipermail/programming/2017-August/048143.html
The code snippet Farey is an example of the source code of the little
compiler.
I just think we should not have to use a tacit J compiler from explicit J
to be able to use explicit J syntax and get a tacit result, a single
verb.
It would obviously be better to use explicit J  syntax in the first
place,
as i see it.

Cheers,

Erling


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