Re: Latin-1 non breaking space not highlighted

[Kenichi Handa <handa@etl.go.jp>]

"Stefan Monnier" <monnier+gnu/emacs@RUM.cs.yale.edu> writes:
>>  My point is:
>>  show-trailing-whitespace should not mean highlighting such
>>  charactes that have "whitespace" SYNTAX, but should mean
>>  highlighting sucn characters that have "whitespace" GLYPH.

> That's a separate issue.  Related to whether or not we should
> take the display-table into account.

In my understanding, the purpose of show-trailing-whitespace
is to tell users that there are characters that has space
glyphs (thus invisible) at end of line.  So, yes, if some
characters are displayed by SPCs because of display-table,
it is better that we take that info account (although it may
require a rather big change in the display engine).  Anyway,
we should not decide if a character should be highlighted or
not simply by its syntax.

>>  Both sets of characters mostly overlap but not necessarily
>>  be the same.
>>  
>>  For instance, even if I set syntax of NBSP to "word
>>  constitute",

> When would you do that and why (considering that we're specifically
> talking about the global standard-syntax-table) ?

The above is just an example.  I don't mean it's useful.
But, hmmm, perhaps, it may be useful for filling.

>>  show-trailing-whitespace should highlight it.

> Really ?  I think this very much depends on the answer to the
> previous question.

I really think NBSP should be highlighted also in such a
(hypothetical) situation.  What do the other people think?

> We really just need a table somewhere that tells us what is whitespace
> and what isn't.  Currently I think there are two such tables, one is
> the standard-syntax-table, the other is the ` ' category.  Actually,
> I [:space:] and [:blank:] are two more, but [:space:] relies on the
> buffer-local syntax-table (i.e. not good, although it's not that bad
> since it only uses it for non-ASCII chars, IIRC) and [:blank:] only
> matches ASCII chars (i.e. not good either).

I have forgotten about ` ' category.  Do you know which
character has this category and how is that category used?

---
Ken'ichi HANDA
handa@etl.go.jp