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Subject: Re: [SG16-Unicode] [isocpp-core] What is the proper term for the locale dependent run-time character set/encoding used for the character classification and conversion functions?
From: Corentin (corentin.jabot_at_[hidden])
Date: 2019-08-14 11:48:49


On Wed, Aug 14, 2019, 4:57 PM Peter Dimov <pdimov_at_[hidden]> wrote:

> Tom Honermann wrote:
> > On 8/14/19 3:54 AM, Peter Dimov wrote:
> > > Tom Honermann wrote:
> > >
> > >> I think we *might* be successful in using "execution encoding" to
> > >> apply to both the compile-time and run-time encodings by extending
> the
> > >> term with specific qualifiers; e.g., "presumed execution encoding"
> and
> > >> "run-time/system/native execution encoding".
> > >
> > > This would be implying that there's a single "execution" or "native"
> > > encoding, whereas there are many.
> > >
> > > - encoding used for character literals
> >
> > I made the "presumed execution encoding" distinction specifically for
> this
> > case.
>
> Right, and I am saying that calling all the encodings "<adjective>
> execution
> encoding" implies that they are if not the same, then somehow related, and
> they aren't.
>
> I would call the encoding used for narrow character literals "narrow
> literal
> encoding" and the encoding used for wide character literals "wide literal
> encoding". This is what they are.
>

I strongly agree. Someone should write a paper :)

>
> "Execution encoding" made sense when a program was, say, written in
> Krasnoyarsk and intended to be executed in Kuala Lumpur. A Krasnoyarsk
> machine used the Krasnoyarsk encoding for everything, and a Kuala Lumpur
> machine used the Kuala Lumpur encoding for everything. Hence source and
> execution..
>

+1

>
> ...
> > > (*) Here "none" (arbitrary NTBS not interpreted as characters by the
> FS)
> > > is an option
> >
> > Except that, historically, some implementations apply locale
> > transformations to *some* of the filesystem interfaces. For example,
> > paths passed to std::fstream may be converted in a locale sensitive way
> > while paths passed to std::wfstream may not be.
>
> Right, some FSs accept arbitrary NTBSs and guarantee a perfect roundtrip,
> and others do not and do not. But that's library. The point is that there
> is
> no single system execution encoding. Different parts of the system use
> different encodings.
>
>



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