On Fri, Nov 05, 2010 at 01:59:54PM +0100, Manuel Pégourié-Gonnard wrote: > Hi, > > Sorry if this is very clear from the manual, maybe I just didn't read the part > where it is explained (or I read it but was too stupid/tired to notice), but I > don't understand the meaning of the return value of some callbacks. > > The first example (by order of apparition in the manual) is > pre_linebreak_filter, whose calling convention is: > > function(<node> head, <string> groupcode) > return true | false | <node> newhead > end > > I think it's clear what returning a newhead node does, but I don't understand > what returning true or false means for this callback. Other similar callbacks > include post_linebreak_filter, (h|v)pack_filter, pre_output_filter, etc.
I think it is explained in section 4.1: For some minor speed gain, you can assign the boolean false to the non-file related callbacks, doing so will prevent LuaTeX from executing whatever it would execute by default (when no callback function is registered at all). Be warned: this may cause all sorts of grief unless you know exactly what you are doing! This functionality is present since version 0.38. Not sure about "true" though. Regards, Khaled -- Khaled Hosny Arabic localiser and member of Arabeyes.org team Free font developer _______________________________________________ dev-luatex mailing list dev-luatex@ntg.nl http://www.ntg.nl/mailman/listinfo/dev-luatex
