gtk+ and word selection

[dAgeCKo <dagecko free fr>]

hello all,

I've been spending a lot of time to know if it's possible and how to 
manage the word selection within a gtk TextView or TextBuffer (like 
setting what are the word boundaries when you double click on a word), 
but all the best I could get is that this is hard written in the pango 
word breaking algorithm (cf 
https://mail.gnome.org/archives/gtk-i18n-list/2011-August/msg00000.html).

What I'm currently doing is a C++ code editor. For example when I select 
a word, the word is separated by the underscore character, thing I want 
to modify. Ie, when I double click on my_variable, whether my or 
variable is selected depending on where the cursor is.

I know most of Gtk+ editors behave like this, but I also know that some 
Gtk+ editors (medit for example) behave the good way.

I also want to be able to move to the next word when doing the <ctrl> 
<right> keys combination which again medit is doing fine, but not anjuta 
for example.

So my question is simple. How can I modify the word boundaries in a Gtk+ 
program ? Maybe you can point me to some useful documentations that 
explain this point ?

I am targetting Gtk+ 3 (in fact Gtkmm 3), but I would also appreciate if 
the trip could work with Gtk+ too.

Thanks in advance.

Regards.