First off, I don't think you understand J syntax.
This is, syntactically, a single word within J:
1 2 3 4 5
And, similarly, this is (syntactically) a single word within J:
'this is a test'
But, also, this is a syntax error in J:
't' 'e' 's' 't'
But just because that's a syntax error doesn't mean that 'test' is invalid in J.
....
So one of the things we're going to have to work through will be these
issues of understanding.
...
Anyways... unanswered questions:
(1) When a key from x appears several times within y, how is that
reflected in the result? Why?
(2) When a key from x is missing from y, how is that reflected in the
result? Why?
(3) What constraints exist on keys from x (can a key be a sequence?
What are the rules for unboxing keys from x before they are looked for
in y?)?
(4) What constraints exist on values from y? (Obviously, they must
conform or the result cannot be assembled. But under what rules are
they organized?)
And, what -- specifically -- is the rule for associating a key within
y with the corresponding value within y? (This is probably obvious,
but it's worth stating because we're tripping over conflicts between
unstated assumptions.)
Thanks,
--
Raul
On Thu, Feb 20, 2020 at 3:00 AM Raoul Schorer <raoul.scho...@gmail.com> wrote:
>
> Raul,
>
> I realise that my questions are somewhat awkward and I'm doing things
> that are way too complicated for me, but that's what I like about them
> so sorry if I was unclear.
>
> The requirement is that I would like to substitute members of x with
> those of y in a strict fashion, where x may be of any shape or type.
>
> * The simplest case, as you stated: 1 2 (1&{::@] {~ 0&{::@] i. [) (2
> 1;4 9)
> * But x may be boxed and y elements of different types: (1;2) (] {~
> 0&{::@] >:@i.>@[) (2 1;'a';9)
> * Also, the substitution being strict, it should respect syntactic
> rules: 1 2 find (2 1;'';9) NB. should fail, as 9 '' yields a syntax
> error
>
> I hope I am making more sense?
>
> > if that's doing what I think it's doing, it would be better handled
> by omitting the associated keys from the data structure.
> Can you explain a bit more of what you mean by that?
>
> Thank you very much for taking the time to help me!
> Raoul
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