SH dispatch

[josh]

Adding a collection of required sh functions isn't going to fly for rbenv. We are making some exceptions for stuff like shell completion where the functionality isn't essential.

I think this is a really nice lightweight convention for defining custom shell helpers. A small rbenv command dispatcher is installed at init. Regular commands pass though as you'd expect. But special shell commands prefixed with sh- are called, but its result is evaled in the current shell allowing them to modify environment variables. Whats really cool is this is now a simple plugin framework for anyone to write custom rbenv shell commands.

I think we'll start with rbenv-use for now. Its basically an alias for export RBENV_VERSION.

[metaskills]

Sexy!

[tmking]

I like this. Very clever and elegant.

[tmking]

@josh,

I added some error handling and a few other minor things. Should I open a pull request against the sh branch? Or should I wait for this pull request to be accepted and open it against master?

[josh]

I need to see what Sam thinks.

The completion stuff needs to be fixed for this. Thinking rbenv commands should list everything (local, version, use). Then add some flags for restricting it to sh commands rbenv commands --sh and rbenv commands --not-sh-bad-name.

[josh]

@sstephenson ping!!!

Probably just going to merge this soon :)

[sstephenson]

I know I'm late... but this is great. Thanks @josh.

[josh]

Ah, yeah I forgot about the shell change.