Re: [PATCH] Unicode Lisp reader escapes.

[Aidan Kehoe]

 Ar an seachtú lá déag de mí Meitheamh, scríobh Eli Zaretskii: 

 > >  > Is it to trigger an "Invalid character" message, or is something else
 > >  > going on here?
 > > 
 > > It doesn't actually trigger a message, it displays a character to be
 > > interpreted as ``the character couldn't be interpreted.''
 > 
 > But in my testing, I do see an "Invalid character" message.

Yes. That’s because I yanked the wrong charset from charset.h when porting
the code from XEmacs, and the attempt to create two-dimensional character in
JISX0201 fails, as it should, since JISX0201 is a one-dimensional character
set. 

The code as intended, doesn’t trigger the message. As it was written, to my
discredit, it did.

 > Could you please show an example of using this new function to produce
 > this special ``character that couldn't be interpreted''?

 > > My feeling is that the syntax should be close in its behaviour to what the
 > > coding systems do, and when the coding systems see a code point that is
 > > valid but that they can't interpret, they trash the user's data.
 > 
 > This function is not about coding systems, it's about character sets.

This function is about transformation from an external format to the
editor’s internal format. Which is a big part of what coding systems do. So
some parallels in our approach is reasonable.

 > Coding systems already replace unsupported characters with `?'  (other
 > applications behave like that as well), so perhaps we should use some
 > more conventional character here.
 > Does anyone have an opinion?

Perhaps, indeed.

-- 
Aidan Kehoe, http://www.parhasard.net/