Supporting options vs positional argument separators

[scop]

It would be nice to have some kind of general way or helpers to support doing the right thing after the separator between options and positional arguments. Typically this separator is --, but not always, sometimes it's e.g. - (which in most other contexts tends to mean stdin/out).

I have not thought about this beyond this much at all, but at least it needs to be made so that we don't just complete filenames after a -- because the positional args following it may be some other things than filenames. It also needs to be made optional, because not everything supports it.

Could also discuss/think some if we'd offer the plain separator as a completion. I think we're somewhat inconsistent on this at the moment (although the separator is rarely offered). It's kind of often implicitly/accidentally offered for programs that offer long options as -<TAB> and --<TAB> likely stop at --. Maybe that's good enough 🤷

Niche use case because people don't tend to write the -- (and it's rarely actually needed), but anyway.

[akinomyoga]

I once tried to implement in one of my branches refactor-api-dev a generic argument parsing to make the parsing consistent. The changes can be checked in diff 6f03827eb..3963cd236. The initial motivation was to replace hardcoded argument loops in each completion and bash_completion with a single generic function that performs generic argument parsing. In this implementation, -- is considered by default and could be turned off with flag -N.

However, I discarded this branch because of heavy conflicts. Maybe I can revisit this.