RE: highlighting non-ASCII characters

[Drew Adams]

> DA> But it occurred to me that besides different categories 
> DA> of such critters there might be different levels of
> DA> fontification details that users might want to see.
> 
> DA> For example, for some users or for some purposes, it 
> DA> might be useful to see different kinds of quote marks
> DA> distinguished (e.g. different kinds of curly quotes
> DA> that might be homoglyphs or curly vs straight quotes,
> DA> which are not homoglyphs). For other users or for other
> DA> purposes such highlighting would be a distraction.
> 
> I'll set up a flexible mechanism, probably patterned after
> whitespace.el, to do this kind of highlighting.  So the users will be
> able to extend it if needed.
> 
> I don't know about curly vs. straight quotes.  I don't think that's a
> significant problem, whereas a Cyrillic K in Roman text can actually
> cause problems and security compromises.  I'm not against the idea, I
> have just never seen it become an issue, and there's a million ways to
> combine quotation marks depending on the context.  What's the specific
> case that you're thinking of?

Nothing special. I know that in Framemaker we consistently replace all curly
quotes with straight quotes, mainly so that copy+paste of doc examples will work
in applications (e.g. SQL).

The point was that besides multiple kinds of curly-quote characters that are
true homoglyphs (dunno if such exist; I'm assuming they do), it can also be
useful to highlight a character (e.g. curly quote) that is similar to but not
identical to another character (e.g. straight quote).

That use would be contextual, of course: you might turn it on the same way you
might turn on an on-the-fly spell-check, to let you know whenever you type or
paste the wrong char.

Probably this need would be taken care of by what you described in your first
paragraphs (not quoted here): being able to highlight similar looking chars that
are not necessarily exact homoglyphs.