Re: How to create a derived encoding?

[David Kastrup <dak@gnu.org>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> So if there was a tolerably working way to derive a special encoding
>> (which will be used as a process output encoding) that reconverts
>> control sequences like the above before composing unicode characters
>> from the resulting utf-8 stream, this would appear to be by far the
>> fastest and convenient way to go about this problem.
>
> I'm not sure what you've tried and what are the constraints under which
> you're coding, but I'd have assumed that you can do:
>
> 1 - assume the raw TeX output with its funny quoted bytes is in the
>     current temp buffer.   The buffer is in unibyte mode.

No good.  We are talking about process output that is accumulating in
a buffer.  We can't just let everything trickle in in raw mode since
the buffer may be interactive and so we need to have more or less
accurate stuff at each point of time.

> 2 - do a search&replace of ^^NN to the corresponding byte.

Dead slow if we have to do this with search-and-replace in the filter
routine of the process.

> 3 - call decode-coding-region with the appropriate coding system.
> 4 - set the buffer to multibyte.

The buffer comes into being incrementally.

> If the step number 2 is too slow, you can most likely implement a
> CCL program that does it faster.

Well, that was what I was asking about.  And how to let this CCL
program run prefixed to the normal process output decoding program.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum