I got the ground-works for {T7984} ready, and was trying to implement another source, when I hit the fact that for non-php, we do really bad job at detecting what words should be searchable.
For most languages, this is a really hard problem, because figuring out if a name is global (searchable) or local, or a variable or a method, or finding the right context, requires more power than a lexer can get.
So maybe leave it to the user to say "This is a word I want to search", by holding down the ctrl key?
Have we tried this before?