[luatex] Request for Callback

[Hans Hagen]

On 6/27/2013 11:45 AM, Élie Roux wrote:

> For the second and third case, the new clef will already be in a
> localleftbox, so it's useless to print it, it should simply be removed.
> If this new callback was present, I could remove the cc character before
> TeX evaluates if the linebreak is good or not...

it would complicate the already complex algorithm and once we start 
adding callbacks *in* core mechanisms we notonly get a slow down but 
also an endless list of additional subcallbacks and dependencies

> If you think this callback is a bad idea, is there somewhere an
> implementation of a librebreak_filter callback in Lua? It wouldn't have
> to be precisely the same implementation as TeX, it can be simplified...

maybe gregorian can do with a real simple linebreak function written in 
lua, not hampered by hz, protrusion, hyphenation, etc (such a fucntion 
can then be enabled selectively)

btw 1, i do have the current algorithm in lua (already for a few years) 
and in the process came up with a more efficient and clean hz 
implementation (which currently gets investigated / implemented in the 
backend, but with a low priority) ... so at some point a context will 
provide a more tunable parbuilder in lua (i considered useful at all)

btw 2, for complex arabic context provides an optimizer that runs on top 
of the standard parbuilder ... using some extra font juggling ... pretty 
slow btw

Hans

-- 

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------