Add an editor option for keeping completion placeholders.

[gibbz00]

I keep finding myself having to retype them again.

Possibly relevant commit: ba24cfe

[pascalkuthe]

see #7045

[gibbz00]

I did see some PR/issues regarding completion handling, and I do understand that support isn't entirely there yet. Ideally, I would love to be able to have a keybinding that it inserts the virtual placeholder text before "tabbing" to the next placeholder.

Right now, however; all placeholders are removed as soon as the first argument is being filled in, which kind of defeats the purpose of having them in the first place.

It is also a lot more efficient for me to retype the arguments that don't have variables of the same name already in scope, than to retype those that do. This was the primary motivation for this PR.

test.mp4

Now, I don't want to say that one way is better than the other, but this gives users at the very least a choice until the underlying completion system is fledged out.

[AloeareV]

I am enthusiastically in favor if this feature!

[ModProg]

I have this use case quite often, when e.g., implementing traits in rust, by calling said trait's function on a field.

I'd be fine with having them replaced as soon as you start typing when navigating to one of them, but keeping them when not replaced.

[So1aric]

Yep, this is also helpful when writing C code. For example, when you define a prototype in a header file and go to a C file to implement it, Clang will give a snippet which is pretty helpful. However, Helix will then delete it 😢

[gibbz00]

@pascalkuthe what's the status on this PR?

[the-mikedavis]

#9801 is the proper fix for this