fixup-whitespace for scripts with no inter-word space

[Eric Abrahamsen]

A while ago I posted on emacs.help about improving inter-word boundary
behavior for Chinese prose editing. I was directed to post here, but
also given some good tips. I realized I'm looking at two separate
issues, and I'm posting about the simpler of the two first.

That problem is interword spaces -- Chinese doesn't put spaces between
words. I was pointed at fill-nospace-between-words-table, which sure
enough knows all about this:

(aref fill-nospace-between-words-table ?中) -> t

This is used in fill-paragraph (actually fill-delete-newlines) to good
effect. I realized what was actually annoying me was delete-indentation,
which calls fixup-whitespace, which (mostly) unconditionally adds a
space between joined lines.

I did a quick grep of emacs' lisp directory and in the basic libraries,
at least, it seems fixup-whitespace is only called by
delete-indentation.

Would it be acceptable to patch fixup-whitespace so that it does what
fill-delete-newlines does? Ie, rewrite as such:

(defun fixup-whitespace ()
  "Fixup white space between objects around point.
Leave one space or none, according to the context."
  (interactive "*")
  (save-excursion
    (delete-horizontal-space)
    (if (or (looking-at "^\\|\\s)")
            (save-excursion (forward-char -1)
                            (looking-at "$\\|\\s(\\|\\s'"))
            (and enable-multibyte-characters
                 (let ((prev (preceding-char))
                       (next (following-char)))
                   (and (or (aref (char-category-set next) ?|)
                            (aref (char-category-set prev) ?|))
                        (or (aref fill-nospace-between-words-table next)
                            (aref fill-nospace-between-words-table prev))))))
        nil
      (insert ?\s))))

 If this seems acceptable in principle I'll report a bug and provide a
 patch.

 Thanks,
 Eric