Re: Nested definitions

On 2025-07-03 17:11, albert@spenarnc.xs4all.nl wrote:

In article <1043831$3ggg9$1@dont-email.me>,
Ruvim  <ruvim.pinka@gmail.com> wrote:

On 2025-07-02 15:37, albert@spenarnc.xs4all.nl wrote:

In article <1042s2o$3d58h$1@dont-email.me>,
Ruvim  <ruvim.pinka@gmail.com> wrote:

On 2025-06-24 01:03, minforth wrote:
[...]
>

For me, the small syntax extension is a convenience when working
with longer definitions. A bit contrived (:= synonym for TO):
>
: SOME-APP { a f: b c | temp == n: flag z: freq }
\ inputs: integer a, floats b c
\ uninitialized: float temp
\ outputs: integer flag, complex freq
    <: FUNC < ... calc function ... > ;>

>
BTW, why do you prefer the special syntax `<: ... ;>`
over an extension to the existing words `:` and `;`
>
    : SOME-APP
       [ : FUNC < ... calc function ... > ; ]
       < ... >
    ;
>
In this approach the word `:` knows that it's a nested definition and
behaves accordingly.

>
Or it has not even know it, if [ is smart enough to compile a jump to
after ].

>
This can be tricky because the following should work:
>
   create foo [ 123 , ] [ 456 ,
>
   : bar  [ ' foo compile, 123 lit, ] ;

 If this bothers you, rename it in [[ ]].
 Once we enhance [ ] to do things prohibited by the standard,
(adding nested definitions) I can't be bothered with this too much.

The standard does not prohibit a system from supporting nested definitions in whichever way that does not violate the standard behavior.
Yes, something like "private[ ... ]private" is a possible approach, and its implementation seems simpler than adding the smarts to `:` and `;` (and other defining words, if any).
The advantage of this approach over "<: ... ;>" is that you can define not only colon-definitions, but also constants, variables, immediate words, one-time macros, etc.
   : foo ( F: r.coefficient -- r.result )
     private[
       variable cnt
       0e fvalue k
       : [x] ... ; immediate
     ]private
     to k   0 cnt !
     ...
   ;
It's also possible to associated the word list of private words with the containing word xt for debugging purposes.
--
Ruvim