Re: [PATCH 6/7] stage: add 'diff' subcommand

> A more notable aspect of the above list is not the similarity but
> difference from the rest of Git.  The above organizes various
> operations on the staging area in a single command as its operating
> modes, so you'd use "git stage --diff" for comparing with the
> staging area but use something else ("git commit --diff HEAD"???).
> 
> It is a good example that illustrates that the proposed organization
> may not help learning or using the system for operations that also
> apply to other things like commit and working tree (in other words,
> "git stage --grep" may not be such a good idea for the same reason
> as "git stage --diff").  But if it were limited to operations that
> apply only to the index (e.g. "git add" and "git rm"), it may be an
> improvement (I think we added "git stage" synonym exactly for that
> reason, already).