Re: [PATCH] technical doc: add a design doc for the evolve command

From: SZEDER Gábor <szeder.dev@gmail.com>
Date: Nov 19, 2018, 15:55 UTC
Message-ID: <20181119155545.GT30222@szeder.dev>
In-Reply-To: <CAPL8Zitk1UBxpVCRWc-SV+1MtaOCJUOYUqCh7eJQcdR_wqpNfQ@mail.gmail.com>

On Sat, Nov 17, 2018 at 12:30:58PM -0800, Stefan Xenos wrote:

Show 11 quoted lines

> > Further, I see that this document tries to suggest a proliferation of new commands
> 
> It does. Let me explain a bit about the reasoning behind this
> breakdown of commands. My main priority was to keep the commands as
> consistent with existing git commands as possible. Secondary goals
> were:
> - Mapping a single intent to a single command where possible makes it
> easier to explain what that command does.
> - Having lots of simpler commands as opposed to a few complex commands
> makes them easier to type.
> - Command names are more descriptive than lettered arguments.

Subcommand names and --long-options are just as descriptive.

> Git already has a "log" and "reflog" command for displaying two
> different types of log,

No, there is 'git log' for displaying logs in various ways, and there is 'git reflog' which not only displays reflogs, but also operates on them, e.g. deletes specific reflog entries or expires old entries, necessitating and justifying the dedicated 'git reflog' command.

> so putting "obslog" on its own command makes
> it consistent with the existing logs, easier to type, and keeps the
> command simple.

> - We could turn "obslog" into an extra option on the "log" command,
> but that would be inconsistent with reflog and would complicate the
> already-complex log command.

On one hand, it's unclear to me what additional operations the proposed 'git obslog' command will perform besides showing the log of a change. If there are no such operations, then it can't really be compared to 'git reflog' to justify a dedicated 'git obslog' command.

OTOH, note that 'git log' already has a '--walk-reflogs' option, and indeed 'git reflog [show]' is implemented via the common log machinery. And this is not a mere implementation detail, because "git reflog show accepts any of the options accepted by git log" (quoting its manpage), making it possible to filter, limit and format reflog entries, e.g.:

  git reflog --format='%h %cd %s' --author=szeder -5 branch file

I think 'git obslog' should allow the same when showing the log of a change.

> Personally, I don't
> consider a proliferation of new commands to be inherently bad (or
> inherently good, really). Is there a reason new commands should be
> avoided?

If a user wants to deal with reflogs, then there is 'git help reflog' which in one manpage describes the concept, and how to list and expire reflogs and delete individual entries from a reflog using the various subcommands. If a user wants to deal with stashes, then there is 'git help stash', which in one manpage describes the concept, and how to create, list, show, apply, delete, etc. stashes using the various subcommands. See where this is going? The same applies to bisect, notes, remotes, rerere, submodules, worktree; maybe there are more. This is a Good Thing.

By adding several new commands users will have to consult the manpages of 'evolve', 'change', 'obslog', etc., even though the commands and the concepts are closely related.