Among the editors which handle well ligatures is Geany. The cursor moves always over a character, regardless whether it is part of a ligature or not. You can s

Among the editors which handle well ligatures is Geany. The cursor moves always over a character, regardless whether it is part of a ligature or not. You can select and delete or replace only a part of a ligature, exactly in the same way as when using a font without ligatures. The only thing that ligatures change is the visual appearance of the text, which is in my opinion an extremely useful workaround for the inertia of the legacy programming languages, which continue to use the restricted ASCII character set, which has never included all the characters that would have been needed in a programming language. Now with ligatures, we are finally able to write an ALGOL 60 program that looks like it was intended to look, 65 years ago, instead of being forced to use awkward combinations of ASCII characters, like later programmers and designers of programming languages have resigned themselves to do, because of the character set limitations that the American manufacturers of computing equipment have been unwilling to remove (causing problems not only to programmers, but also to the users of non-English languages). ASCII has never been intended to include the characters required for writing mathematical expressions. ASCII has been intended only to include the set of characters that were in use in the commercial correspondence written in English, which had been previously available in the better typewriting machines. Because of this, ASCII has always been bad as a character set used for a programming language.