Re: lax matching is not a great default behavior

[Eli Zaretskii <eliz@gnu.org>]

> Date: Fri, 4 Dec 2015 07:55:34 -0800 (PST)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: jwiegley@gmail.com, rms@gnu.org, emacs-devel@gnu.org
> 
> > > > If we are afraid users will hate this default, we can turn it
> > > > off in v25.1 and consider making it the default later.
> > >
> > > That would be good
> 
> You snipped the rest of Per's point there, which makes a
> difference, I think:
> 
> > > , together with introducing an entry for it in the Options
> > > menu directly below (or above?) "Ignore case for search".
> > > This deserves to be as visible as that option.

I don't see how that is relevant.  Menu options have very little
relevance to the defaults.  And yes, I agree that there should be such
an option in the menu bar's menus.

> _Has_ such a decision to change the default behavior in fact already
> been made?

Yes.  The code that makes it the default didn't just write itself.

> > Character folding was introduced with the explicit goal of giving
> > users what the other text-editing and word-processing environments
> > provide, what they therefore are expected to expect.
> 
> So what?  So was CUA mode and lots of other features that are
> not turned on by default.

Yes, there are examples to the contrary as well.  But that's besides
the point.  The point in that part of the discussion was the claim
that features that mean massive changes must never be made ON by
default.  To refute that, all I need is a single significant example
to the contrary.  Which is what I provided.

> Bidi did not noticeably affect users who do not edit bidi text.

Likewise with character folding: as long as you search text where no
equivalent characters exist, you will see no difference at all.

> I think that a much better comparison is CUA mode.  You argue
> that we should turn char folding on by default _because_ that's
> what users of other editors are used to.  Most users of other
> editors are used to CUA-like behavior too.  Yet we don't turn
> that on by default (and I agree with that decision).

I'm not going to start arguing about CUA.  I will just say that CUA
was problematic because it actively _conflicted_ with many basic Emacs
keybindings.  That was the single most important problem that
justified its being off by default.  There's no such incompatibility
in the case in point.

> > > Should it be "Ignore accents for search"?
> > 
> > No, because ignoring accents is just a small part of character
> > folding.  Please take a look at character-fold.el for the details.
> 
> Agreed.  And neither is it folding of diacriticals, because there
> are also ad hoc foldings (e.g., quote marks).  And there will
> likely be more to come.  It is, in fact, a hodge podge of foldings
> - pretty much all of the various char foldings provided by Emacs
> so far, except for letter case.

Actually, it's not a hodge-podge at all.  Barring any user-level
customizations, it can be formally defined (and has been defined
elsewhere) what is and what isn't folded.

> Why not leave it off by default, for now?

"Why not" is not a compelling argument, sorry.  It cannot win the "why
not" argument in the other direction.

> > turning it off today means that it will get much less testing,
> > and therefore bugs related to it...will most probably remain
> > hidden for who knows how long.
> 
> I seriously doubt that.  That sounds alarmist, to me.

This is in fact based on actual experience of testing new features in
Emacs, during several pretests of a few major releases.

> My expectation, if we turn it off by default, is that users will
> try it, like it, and possibly ask for it to become the default
> behavior.

OTOH, if we turn it off by default, users might not even find it or
know it exists for another 5 years.