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From: peter <peter.noreply@tin.it>
Newsgroups: comp.lang.forth
Subject: Re: Nested definitions
Date: Thu, 3 Jul 2025 19:42:02 +0200
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On Thu, 3 Jul 2025 20:47:07 +0400
Ruvim <ruvim.pinka@gmail.com> wrote:

> 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 (:=3D synonym for TO):
> >>>>>
> >>>>> : SOME-APP { a f: b c | temp =3D=3D n: flag z: freq }
> >>>>> \ inputs: integer a, floats b c
> >>>>> \ uninitialized: float temp
> >>>>> \ outputs: integer flag, complex freq
> >>>>>    =A0<: 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, ] ;
> >=20
> > If this bothers you, rename it in [[ ]].
> >=20
> > Once we enhance [ ] to do things prohibited by the standard,
> > (adding nested definitions) I can't be bothered with this too much.
>=20
>=20
> The standard does not prohibit a system from supporting nested=20
> definitions in whichever way that does not violate the standard
> behavior.
>=20
>=20
> 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).
>=20
> 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.
>=20
>=20
>    : foo ( F: r.coefficient -- r.result )
>      private[
>        variable cnt
>        0e fvalue k
>        : [x] ... ; immediate
>      ]private
>      to k   0 cnt !
>      ...
>    ;
>=20
> It's also possible to associated the word list of private words with
> the containing word xt for debugging purposes.
>=20
>=20
> --
> Ruvim
>=20

In lxf I have module, private, public, end-module
your example would be

module
private

variable cnt
0e fvalue k
: [x] ... ; immediate

public

: foo ( F: r.coefficient -- r.result )
     to k   0 cnt !
     ...
;

end-module

end-module will remove all headers from the private words in the module
I am not found of mixing definitions inside others.

BR
Peter
 =20