refactor: API/naming of functions and a variable in bash_completion

[akinomyoga]

The remaining functions in bash_completion are going to be processed in other PRs:

• refactor: rename { => _comp}{_get_first_arg,_count_args} #1033
  • _count_args and _get_first_arg which are WIP in another branch akinomyoga:refactor-api-2.
  • refactor: refactor _comp_{get_first_word,count_args} #1036
    • Not yet submitted: branch akinomyoga:refactor-api-dev
• refactor: rename variable { => _comp_}root_command plus misc small fixes #1034
  • small fixes that should be applied before refactoring
  • rename variable root_command -> _comp_root_command
• refactor: API/naming of other functions in bash_completion #1035
  • _known_hosts_real, which needs to be updated to be a generator.
  • __expand_tilde_by_ref, _expand, _variables, _services
• refactor: rename completion functions #1037
  • the functions that are supposed to be passed to complete -F. Maybe we can give consistent names to such functions, such as _comp_complete_*

[akinomyoga]

commit e633b62 ({ => _comp_compgen}_shells) was moved to PR #1035 1f8e77c.

[scop]

I'm wondering if this is something we want/need to expose as a public function? External completions shouldn't need to use it I think.

[akinomyoga]

Thank you.

Hmm, ble.sh actually wants to use it. _completion_loader (which is also used by git-completion.bash from the Git project) sets _minimal up when none is found, but ble.sh wants to fall back into its own completion if none is found. Another option is to make _completion_loader accept an option that suppresses the fallback to _minimal.

---

I now noticed that I overlooked _completion_loader in renaming functions. I think _completion_loader should be renamed to _comp_load instead of __load_completion. I'll fix it.

[akinomyoga]

Another option is to make _completion_loader accept an option that suppresses the fallback to _minimal.

I suggested this, but _completion_loader is used as a completion function for complete -F, so I realized it causes a problem when a user inputs a command name starting with - in the command line. So we should prepare two separate functions for complete -F and for a feature to load the completion from a script.

Also, as far as I search on GitHub, __load_completion is directly used by some users (regardless of whether it was originally intended by us).

---

The function _completion_loader currently seems to be intended for two different roles. One is as a function that is specified to complete -F. For example, returning status 124 on successful loading is a part of this use case. The other is as a function that can be called by a user to load a completion for a specific command. Here, I suggest splitting _completion_loader into two: 1) _comp_xxx "$cmd" that can be used to load a completion for the specified command, and 2) _comp_yyy that can be specified to complete -F.

Then, I would also like to have an option that does not define the fallback completion _minimal when the specific completion is not found. I use it for ble.sh. There are also other scripts that use __load_completion (though I'm not sure if they recognize _completion_loader). There are two ways:

• Opt-out _minimal -- _comp_xxx -- "$cmd" defines the fallback setting _minimal by default, and _comp_xxx -R "$cmd" does not.
• Opt-in _minimal -- _comp_xxx -- "$cmd" does not define _minimal, and _comp_xxx -D "$cmd" defines _minimal.

The opt-in behavior seems natural to me as defining _minimal is an additional behavior on top of just loading a specific completion. Actually, the opt-in behavior is mostly the same as the current implementation of __load_completion, so my current suggestion is to merge the feature _comp_xxx (feature 1 of _completion_loader) into __load_completion as an option -D (defining the default setting _minimal) and to make it a public interface under the name _comp_load.

The feature _comp_yyy is named as a function _comp_complete_load in accordance with the naming convention suggested in #1037. I can adjust the naming.

I've pushed those adjustments in commit 77497bc.

[scop]

LGTM, thanks!

[akinomyoga]

Thank you.