Just for the info, we have this filetype_specific.c in TM now and it's called tm_parser.c.
Whilst TM may be the main part, I was thinking about _all_ the places where there are "if Python/C/C++" parts eg `editor.c`, not just TM related. Once its all in one file it becomes easier to add "if using LSP else" to the front of the filetype tests, and/or hive them off to filetype specific plugins. Just needs "somebody" to do it.
I'm kind of proud I set an example here for the rest of the code
A _good_ example in fact, neat :-)
and that in this area TM is is now better than the rest of Geany at least in something :-).
Still nobody (but you) wants to touch it ;-P
Still maybe the cleaner can do it (reference to your last para).