Subject: bug#69968: Case-folding of Mathematical Alphanumeric Symbols

From: Eli Zaretskii <[email-masked]>
Date: Mon, 25 Mar 2024 14:37:49 +0200

> From: Juri Linkov <[email-masked]>
> Cc: [email-masked]
> Date: Mon, 25 Mar 2024 09:37:10 +0200
> 
> >> Ok, then it's very strange that the Unicode standard doesn't define
> >> letter-case conversions for other letters.  But what can we do.
> >
> > We can define case-conversions for them if we decide to do so.
> > Moreover, Lisp programs which for some reason need that can do that
> > themselves, even if by default there are no case-conversions defined
> > for them.  The question is when and why is this needed?
> 
> Probably case-conversions for them could be added later only
> when there is more support for such symbols in Emacs:
> for example, after creating an input method to input them,
> or better a command that will convert the region of ASCII chars,
> etc.

I agree that case-conversions for these characters would make more
sense as part of a larger package which would allow using these
characters as letters.  In any case, making a lower-case character L
and upper-case character U a case-pair is simple:

  (let ((tbl (standard-case-table)))
    (set-case-syntax-pair U L tbl))

The above makes the change global, but it can also be made
buffer-locally; see "Case Tables" in the ELisp manual for more
details.

I guess we can now close this bug?  Or is there anything else to do
here?