On 16.06.2012 10:17, Stefan Monnier wrote:
>>>> 2) sgml-indent-line calls sgml-parse-tag-backward, which does
>>>> (re-search-backward "[<>]"), finds "<" and performs simple regexp check.
>>>> Thus,<% if a<  3 %>  breaks indentation on following lines, until first
>>>> closing tag.
>>> I think we can treat this as a bug in sgml-indent-line, which should try
>>> and use syntax-ppss or something like that instead of regexps.
>> I wonder how that could be fixed exactly. parse-partial-sexp doesn't look
>> helpful, because it works with single characters, and sgml is concerned with
>> full tags. It also has to handle unclosed tags like <br>, some closing tags
>> are optional, and HTML 4 has self-closing tags.
>
> I think just checking after the regexp-match whether the match was found
> within a "comment" should do the trick, assuming we can get syntax-ppss
> (or some extension thereof) to treat "other modes" as comments.

That should work. Looks like currently it looks for comments with
(search-backward), too.

>> If parse-partial-sexp just starts from (point-min), and then skips over
>> "comments", it will never visit submode regions this way, no?
>
> That's why we'd need to hook into syntax-ppss to run parse-partial-sexp
> on a chunk-by-chunk basis, maybe.  Also parse-sexp-ignore-comments also
> affects (for|back)ward-sexp, as well as up-list, which are important
> building blocks for indentation algorithms.
>
>> Another thing to consider - having "visibility" into previous chunks of the
>> same submode may be more harmful than useful in some cases.
>
> That's OK: the low-level code can't know those things, but the
> higher-level code which handles the various chunks can treat different
> chunks differently.  E.g. using narrow-to-region for chunks which need
> to ignore previous text.

Yes, well, except js-indent-line calls (widen) first thing, so
(narrow-to-region) will not help.