Re: Several serious problems

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

In article <200207240325.g6O3PdX04898@aztec.santafe.edu>, Richard Stallman <rms@gnu.org> writes:
>     Do you mean a command something like this?
>     (defun check-coding-system-region (from to coding-system &optional max-num)
>       "Check if the text after point is encodable by the specified coding system.
>     When called from a program, takes three arguments:
>     CODING-SYSTEM, FROM, and TO.  START and END are buffer positions.
>     Value is a list of positions of characters that are not encodable by
>     CODING-SYSTEM.
>     Optional 4th argument MAX-NUM, if non-nil, limits the length of
>     returned list.  By default, there's no limit."

> This could do the internals of the job.  To be useful, it needs a user
> interface.

Ooops, I forgot to include this sentence in the docstring.

If an unencodable character is found, move point to that character.

So, this function can be used both for an internal job and
for an interactive job (to find the next unencodable
character).

> How about if you modify it to make overlays to highlight those characters
> instead of returning a list saying where they are?

If the specified coding system is totally inappropriate for
the buffer, highlighting them will results in huge amount of
overlays and also it takes long time to finish the job.  If
we limit the number of highlighting, it may give users
incorrect information (i.e. non-highlighted characters seems
to be encodable).  So, I thought just moving point to the
next unencodable character is better.

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