Re: [I18ndir] I-D on filesystem I18N

[Nico Williams <[e-mail]>]

On Tue, Jul 07, 2020 at 09:31:55PM -0400, John C Klensin wrote:
> --On Tuesday, July 7, 2020 16:43 -0700 Asmus Freytag
> <[e-mail]> wrote:
> > However, early case-insensitive file systems did not preserve
> > case. Not sure how rare this has become.
> 
> Well, Unix, and every Unix-derived system I know of (definitely
> including Linux, FreeBSD, and NetBSD) are case-sensitive and
> getting anywhere near their file names with Case Folding or even
> lower casing will cause rather interesting problems.  One the
> case-insensitive side, I've heard of a system called "Windows"
> that usually preserves case but does not guarantee to do so and
> many operations, in practice, don't.  

At least ZFS supports case-insensitivity as an option.  ZFS is available
on just about every Unix and Unix-like OS today, and is quite popular.

That said, I doubt anyone enables case-insisitivity in ZFS datasets on
Unix unless they intend to share it with Windows clients and users
expect case-insensitivity.  Indeed, that's the reason that ZFS has this
option at all: Windows interoperability.

> In addition, Asmus caught at least one case where your
> terminology is inconsistent with that of Unicode.  Such

Yes yes, I beg your forgiveness.  I wrote "normal form" instead of
"normalization form".  A silly editing error.

> inconsistencies (at least if not specifically identified and
> justified) are an invitation to reader confusion or worse.  As
> one more example, you should not be talking about case folding
> and then lower casing.  They are different and have different
> implications.  And, fwiw, most of my Turkish-speaking and

Did you not read that text?  I only mentioned lower case in the context
of explaining in introductory text what case-folding is.  And I did NOT
say that they are the same thing.

> writing colleagues would disagree that U+0131 "could" or should
> be considered equivalent to U+0069.  In my experience, that

The idea was to describe how an admin might square that circle in a
case-insensitive filesystem, and then I did not endorse it.  The idea
was to describe how custom case-folding tailorings (FYI, that's the term
Unicode uses, 'tailoring') might come about.

There will be time to address all the nits.  The big idea is more
interesting.

Nico
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