Re: 0 SET-ORDER why?

In article <v5ioud$2ii4l$1@dont-email.me>,
Gerry Jackson  <do-not-use@swldwa.uk> wrote:

On 26/06/2024 14:36, Ruvim wrote:

One possible use case:
>
   : turnkey ( -- ) 0 set-order
     also Target definitions
     also Minimal also
   ;

>
ALSO duplicates the wordlist at the head of the search order. If the
search order is empty there is nothing to duplicate. Therefore ALSO
applied to an empty search order ought to be an ambiguous condition.
>
Presumably the above definition works because a target wordlist replaces
whatever garbage ALSO leaves in the search order. So the definition
might as well have 0 1 SET-ORDER instead of 0 SET-ORDER ALSO.
Or better still TARGET-WORDLIST 1 SET-ORDER. Either removes the above
justification for 0 SET-ORDER.
>
But having said that it is better for 0 SET-ORDER to do what is natural
instead of yet another ambiguous condition.
>

Another possible use case:
>
   : s-to-n ( addr u -- n )
     depth >r
     get-order n>r 0 set-order
       ['] evaluate ['] execute-interpreting catch
     nr> set-order
     depth 1- r> <> if -12 throw then
   ;

>
This is a better use case e.g. if BASE is greater than decimal 10
converting an alphanumeric string to a number could clash with a word in
the dictionary. Having an empty search order eliminates that possibility.
>
Incidentally another possibility is that if ['] EVALUATE is replaced in
the above definition with ['] SOME-RECOGNISER, that could be the basis
for an ANS/FORTH 2012 compatible way of implementing recognisers. If the
recogniser fails restore the search order and try again.

I'm more and more convinced that the ciforth solution to make ONLY
a wordlist and stick all the number stuff (plus strings, say denotations) there
is ideal.
Add the rule that you simply cannot the remove the minimal search order,
which may perfect sense.
The only non-ISO aspect is that FORTH-WORDLIST and SET-ORDER is missing.
This is just as well, implementing SET-ORDER politically correctly
would bloat the ciforth kernel with 20%, at least that is my impression
from the discussion here.

And besides shuffling the wordlists searched for is a terrible idea.
I have not seen a use case for that.
Think of python. If you import all with *, at least the underlying
assumption is that the libraries contain no conflicting names
such that the order doesn't matter. Imagine that you can somehow
"unimport integral *" .
The idea from ENVRIONMENT that was supposed to find out portably what
facilities are to be loaded. No sensible use case.

A sensible use of wordlist is e.g.
ALSO INLINING
INCLUDE modulo.frt
PREVIOUS
This adds INLINING to the search order to have all the operators of
modulo calculations automatically inlined: +m -m *m ^m .
Then back off.
Or adding the ASSEMBLER namespace temporarily to add code words.

Or a word like IMPORT that makes an alias from a named wordlist
into the current wordlist (assuming current=context).

--
Gerry
>

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--
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