Use compsys completion system for zsh

[Farid-NL]

Completions in zsh are done via compctl.
This PR update the completion file to use the 'new' completion system: compsys.

The changeset doesn't include descriptions for commands, it just use the current logic implemented for compctl and use compsys instead.

[mislav]

Thanks! I have pushed some changes:

• the script is now renamed to _rbenv to enable autoloading
• rbenv command completion now includes command descriptions

To try this out, please ensure that the project's completions/ directory is in your zsh's $fpath before it initializes the completion system. After this change ships, I imagine that it should be the responsibility of a package manager to put the _rbenv file into an appropriate location.

Any feedback welcome!

[Farid-NL]

I've pushed a little change.

• compedef directive takes its arguments as commands to which it will complete, whence the change from _rbenv to rbenv.

It wasn't working for me until that. But it works great!

[Farid-NL]

I imagine that it should be the responsibility of a package manager to put the _rbenv file into an appropriate location.

I would imagine the same as well, however, what about people using the basic git checkout installation method?

I suppose it could be indicated in the README that it is necessary to add project's completions/ in the $fpath. Or tweak rbenv-init, to add the directory to $fpath only in zsh shells, as the commit above.

[mislav]

suppose it could be indicated in the README that it is necessary to add project's completions/ in the $fpath.

That's a very good point. Users of “basic git checkout” installation method will have to tweak their zsh environment to get completions working again. This might be slightly disruptive, but I think proper autoloading is a better solution going forward. We can document this in the README and in future release notes.

Or tweak rbenv-init, to add the directory to $fpath only in zsh shells, as the commit above.

That's a solid idea, but changing $fpath has no effect if the completion system has already been initialized. That means that zsh completions for rbenv would either work or not work depending on where eval … rbenv init line is in zsh startup files relative to completion initialization. Since this is a bit tricky, I would rather opt for users (or package managers) managing fpath themselves and not trying to interfere with that process from within rbenv. With that in mind, I might ship this changeset without your last commit. Would that be okay?

[Farid-NL]

Since this is a bit tricky, I would rather opt for users (or package managers) managing fpath themselves and not trying to interfere with that process from within rbenv. With that in mind, I might ship this changeset without your last commit. Would that be okay?

By all means. You're completely right, it might be tricky changing $fpath just like that.