[luatex] linebreak_filter example implementation

[Élie Roux]

Dear all,

For very specific purposes, I need to modify a little the linebreak 
algorithm, removing one node when it's at the beginning of a line. I 
don't really see how to do that without the linebreak_filter, so I'm 
wondering if there is an example implementation in lua that is close 
enough to the TeX algorithm (if it's a simplification it's ok). Is there 
something like this somewhere?

Thank you very much,
-- 
Elie