Using Vala syntax highlighting, numbers extend their green colour to the '.to_string()' method.
The bug can be reproduced just by writing " 42.to_string() ".
I'm using Geany 1.22-2 from the Archlinux repository.
Scintilla (the editing component we use, www.scintilla.org) does not have a Vala lexer, so we use the C lexer as the nearest approximation so that at least some highlighting is available.
Unfortunately 42.to_string() is illegal C so the lexer isn't programmed to handle it. Whilst you might be able to get a patch that makes the C lexer do the Vala thing accepted by Scintilla if it was simple and added no bugs to the C parsing, the proper solution is to add a Vala lexer to Scintilla.
@elextr Should not this be closed, then?