Not a bad write-up. The Rust code snippets can be slimmed down very slightly though. Here's main(): fn main() { let args = os::args(); let

Not a bad write-up. The Rust code snippets can be slimmed down very slightly though. Here's main(): fn main() { let args = os::args(); let washed_args = args.iter().map(|arg| arg.as_slice()).collect::<Vec<_>>(); match washed_args.as_slice() { [_, "review", opts..] => review(opts), _ => usage() } } although I might actually suggest the alternative approach: fn main() { let mut args = os::args().into_iter(); args.next(); // skip program name match args.next().map(|s| s.as_slice()) { Some("review") => review(args.collect::<Vec<_>>()), _ => usage() } } (this approach requires `review()` to take a `Vec<String>` instead of a `&[&str]`, but that's not a difficult change, and we could fix it using a second line of code if we wanted but at the cost of introducing a new allocation, like the original code does) For review() I'd suggest changing the original code: let cwd = os::getcwd(); let have_dot_git = have_dot_git(cwd.clone()); let dot_git_dir: &Path = match have_dot_git.as_ref() { Some(path) => path, None => { panic!("{} does not appear to have a controlling .git directory; you are not in a git repository!", cwd.display()) }, }; to the following: let cwd = os::getcwd(); let dot_git_dir = have_dot_git(&cwd).expect(format!("{} does not appear to have a controlling .git directory; you are not in a git repository!", cwd.display()).as_slice()); This actually leaves `dot_git_dir` as a `Path` instead of a `&Path`, but I think that's better anyway. It also requires `have_dot_git()` to take a `&Path` instead of (what I assume it takes now,) a `Path`, which is an appropriate change as there's no need for cloning the path.