Re: On language-dependent defaults for character-folding

[Richard Stallman <rms@gnu.org>]

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  > > * A per-buffer language preference variable.
  > > * A global value which becomes the default for new buffers.

  > That's unnecessarily restrictive; we can do better with the current
  > infrastructure.

This is not a restiction, it is a feature.  It is meant to enables
people to do something convenient.

  >   Some encodings provide us with charset information,
  > which can be used to deduce the language of the text.  Some characters
  > belong to Unicode blocks that allow identification of the language, or
  > maybe a small group of languages.  In some cases, the text itself
  > comes with metadata which describes the language.  And there might be
  > other sources of information about the language.

If there are useful ways to determine the language from the text, that
work well enough that users won't complain, let's do it.  That would
be an add-on to the structure I proposed.

  > There are other aspects of this that need to be considered, if we want
  > for language-specific searching to be solid.  E.g., what happens with
  > text copied to another buffer which might have a different per-buffer
  > language preference? does it suddenly behave differently when
  > searched?

Yes.  If you want the two buffers to have the same language
preference, then maybe Emacs can guess that for you; if not, you can
specify it.

  > But the most basic issue is that any significant development in these
  > directions require to re-implement the feature on the C level, and use
  > char-tables for folding, like we do with case-mapping.

It needs to use some sort of tables.  Whether they are the current
kind of char table, or some other structure, is something to be
determined.

-- 
Dr Richard Stallman
President, Free Software Foundation (gnu.org, fsf.org)
Internet Hall-of-Famer (internethalloffame.org)
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