Re: RE: [External] : Indentation with spaces

[Christopher Dimech <dimech@gmx.com>]

> Sent: Sunday, June 12, 2022 at 3:43 AM
> From: "Drew Adams" <drew.adams@oracle.com>
> To: "Emanuel Berg" <incal@dataswamp.org>, "help-gnu-emacs@gnu.org" <help-gnu-emacs@gnu.org>
> Subject: RE: [External] : Re: Indentation with spaces
>
> > >>> Why is `indent-tabs-mode' t by default?
> > >>> Tabs should not be used.
> > >>
> > >> The world is split between 3 factions:
> > >> - those users who absolutely cannot tolerate TABs.
> > >> - those users who absolutely cannot tolerate the
> > >>   use of SPC instead of TAB to indent.
> > >> - those users who have a life.

That world view in incorrect.  With Fortran Fixed-Form Legacy Code
you will find people using a variety of styles.  Some use only TABs.
Others use spaces.  The problem is not about the TABS and SPACES,
it is about formatting.

Emacs accepts TABS and SPACES but then forces its own stylistic
arrangement when electric-indent-mode is enabled.  This Emacs feature,
ends up modifying the original code style, something that is commonly
avoided when dealing with very old legacy code.

The point is that whilst emacs allows the introduction of tabs and spaces,
Emacs cannot be allowed to take decisions on where the code is placed in
the buffer, if that conflicts with what the code designer wants to do.

The solution does not look straightforward.  Thusly, a request for a special
setup for a major-mode to cater for these situations is understandable.

> > > Hooray! If the closed-world hypothesis applies
> > > then I can now say I have a life!
> >
> > I don't get it joke
>
> If CWA holds, and we know/assume the world has
> only those 3 factions, and if neither of the first
> two cases holds then the third must be the case.
>
> IOW, if it's not true that you absolutely can't
> tolerate TABs, and it's not true that you
> absolutely can't tolerate SPCs, then you have a
> life.
>
> On the other hand, if OWA holds, maybe something
> other than those 3 cases holds...
>
> > but
> >
> >   The Closed World Assumption (CWA) is the assumption that
> >   what is not known to be true must be false. The Open World
> >   Assumption (OWA) is the opposite. In other words, it is the
> >   assumption that what is not known to be true is
> >   simply unknown. [1]
> >
> > Interesting! OWA seems reasonable but how did they come up
> > with CWA, when is that useful
>
> It's simpler to reason with.  If you don't know
> something to be true then you conclude that it's
> false.  This is a common approach - databases,
> Prolog etc.  Cf. `completing-read' with arg
> REQIUIRE-MATCH = t.

In 1895, the famous british physicist William Thompson remarked
that "heavier-than-air flying machines are impossible".

> Of course, one can interpret "no match" as just
> "dunno" or "unproven", but often it's acted on
> as "false".  And as Tomas perhaps hinted, it's
> not just about classifying as true, false, and
> dunno.
>
> It's about the difference between any such
> closed classification and a representation or
> system that's based on the idea that both
> (a) the set of stuff that's classified and
> (b) the classification of that stuff both
> (1) are inherently incomplete and (2) can
> change.
>
> CWA is akin to not-proven-guilty-means-innocent
> (or not-proven-innocent-means-guilty).  OWA
> assumes only that not-proven means not-proven.
>
> > and what's closed about it,
>
> It doesn't allow for the possibility that there
> are unknowns.  It assumes that, at any time,
> what's known to be true is all there is.
>
> It's a useful simplification.  But it presents
> difficulties wrt the nature of real knowledge
> and its evolution.
>
> > that you know what you know to be true and every thing else
> > you then and by that can tell is false. So it's a complete
> > state of the knowledge sphere, that's what's closed about it?
>
> Exactly.  At any given time.  And a system that
> allows for increasing or changing knowledge has
> somehow to deal with non-monotonic changes in
> what's known (in particular).
>
> > [1]
> > https://urldefense.com/v3/__https://www.dataversity.net/introduction-
> > to-open-world-assumption-vs-closed-world-
> > assumption/__;!!ACWV5N9M2RV99hQ!NmVaOzeFvXD6WCus5nkkRpZP7Fiih7FVO7UUsEX
> > d-B3ZRQ6mzozldTZQvG4Re0gXUeyMdIAKE0Bpn36B$
>
>