Re: utf-16le vs utf-16-le

[David Kastrup <dak@gnu.org>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>>> > I don't know, in fact I think I think [having BOM-specific coding
>>> > systems is] a bad idea.  That's what the part of my message that
>>> > you snipped was saying.  But I'll have to defer to Handa-san on
>>> > that.
>>> 
>>> I think it obvious: if a BOM mark gets detected on read, one wants
>>> to have it removed from the buffer and reinserted on saving the
>>> buffer.
>
>> I agree, as you state it, it's obvious.  My question is "why does that
>> need to be part of the coding system?"  At present the UTF-16 and
>> UTF-32 Unicode coding systems (in the abstract) have *twenty-seven*
>> variants each (BOM-required, BOM-prohibited, BOM-autodetected X be,
>> le, system-dependent X CR, LF, CRLF), and UTF-8 needs *nine*.  This is
>> nuts, from a user-education standpoint.
>
> For what it's worth, I do think it would make sense to try and move
> the BOM-processing outside of the coding-system proper.  For me a good
> test for coding-system-worthiness is "what if I use it for a process
> rather than a file".  Based on this test, I'm not sure if BOMs really
> fit in (other than for auto-detection and automatically stripping
> them, maybe).

Hm?  I don't see why starting communication with a BOM or not would
_not_ fit in.

>> What I proposed was a more generic concept where use of signatures
>> and the EOL convention would (at least to the user) appear as
>> buffer-local variables.
>
> Here, I disagree: EOL processing definitely need to take place when
> talking to subprocesses, so EOL-handling doesn't belong in
> buffer-local vars but in the coding-system.

I don't quite see the difference to BOM processing, even though the BOM
processing has to happen only once at the start.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum