Command line interface for 2.0

[topecongiro]

Notes on some ideas for CLI changes in rustfmt 2.0.

Deprecate --backup

This should be done via any version control system.

Add subcommands

Change format-diff/git-rustfmt into rustfmt's subcommands.

Also rustfmt --print-config could be one of subcommands as well instead of being a flag, as it takes multiple arguments.

Add --check to cargo fmt

cargo fmt -- --check is one of the most common usage of rustfmt. Why require an additional --?

[calebcartwright]

Add --check to cargo fmt

I'd like to work on that one!

[davidalexanderr]

Hey @topecongiro, is add --check to cargo fmt still up for grabs?

[calebcartwright]

The addition of --check to cargo fmt and the deprecation of --backup have already been completed. I don't think anyone is working on any of the subcommands though

[calebcartwright]

@topecongiro - the only thing left here is to move format-diff/git-rustfmt from separate binaries to subcommands on rustfmt right?

[topecongiro]

Yes, that's right. And since both of them aren't stable yet, I might as well remove them from the 2.0 milestone.

So there's nothing left to do with this issue, closing 🎉