It is quite difficult to compose "input text" of language
such as Japanese by Input Methods like "Kotoeri" on MacOSX,
because emacs does not show clause boundary of the "input text".

I made an attached patch which improves text composition
by making a highlight on active clause of the "input text".

See also attached screen shots which shows effect of this patch:

  before.png: Before applying this patch,
              no clause boundary is shown.

  after.png:  After applying this patch,
              clause boundaries are indicated by
              a highlight on active clause.


In GNU Emacs 23.2.1 (x86_64-apple-darwin10.4.0, NS apple-appkit-1038.32)
 of 2010-10-26 on mac
Windowing system distributor `Apple', version 10.3.1038
configured using `configure  '--with-ns''