[Alpine-info] UTF-8 test message for your viewing (dis?)pleasure

[Mark Crispin]

On Mon, 9 Mar 2009, Eduardo Chappa wrote:

> [Mark, (and everyone else) please do not attack me in a public forum.


If you do not like being corrected in public, then don't make false 
statements that need correcting in public.


> There is no guess in the code. The decision of the code is clear.


There you go again.

You see something in a snippet of code, assume that you now know all that 
there is to know, and then contradict me.

You don't know everything that there is to know.  There is more to the 
width calculation than the code that you found.


> But there is a problem, and it needs to be fixed. Would you

> like to help solving that issue?


Don't you understand yet?

There is no solution.

There are only compromises.  A compromise will work well in some cases and 
less well in other cases.

You can optimize for your particular environment, at the cost of 
pessimizing some other environment.

Windows Alpine double-width displays the codepoints that are reported as 
double-width.  UNIX Alpine could do something similar by sending a cursor 
positioning command after each character.

Since there is also the possibility of zero-width and single-width guesses 
being wrong (more compromises), this has to be done after ALL characters, 
not just double-width.  Otherwise you haven't "fixed" it, you have just 
done a different compromise.

The users will be unhappy at how much slower and bandwidth-intensive 
display has become.

The real solution is to give up on the notion of Alpine running in a 
terminal emulator.  If UNIX Alpine were to display in an X window (NOT 
under xterm, but as its own X window application), it becomes possible to 
use the knowledge gained from having the rendering engine in the same 
application to do correct width judgements.

That is the ONLY solution for characters (e.g., Arabic) that have no 
meaningful fixed-width representation.

The only problem is, I don't know why anyone would want to use the result. 
There are many GUI-only email clients which have a huge head start.

The lesson that you should learn from all of this is that, sometimes, what 
seems to be a "simple" solution is neither simple nor a solution.

-- Mark --

http://panda.com/mrc
Democracy is two wolves and a sheep deciding what to eat for lunch.
Liberty is a well-armed sheep contesting the vote.