In snnipets, add a key to jump to next comma.

[So1aric]

When LSP suggests a snnipet for function, it might look like:

func(, , ,)

And if I want to move to the next comma after I finished the first argument, I have to ESC -> l -> l -> i, which is a burnout.

[gabydd]

Snippets aren't fully implemented, I think we can track this in one issue so I am going to close this as a duplicate of #395