Re: [RFC PATCH 00/11] Sequencer Foundations

[Ramkumar Ramachandra <artagnon@gmail.com>]

Hi Jonathan,

Jonathan Nieder writes:
> Ramkumar Ramachandra wrote:
> > 0. Is the general flow alright?
> 
> Not sure --- I don't have the big picture.  Could you give a quick
> summary of the flow in the cover letter ("patch 1 does such-and-such,
> so patch 2 can do such-and-such, leading to...") to the next revision,
> and quick explanations of the purpose (i.e., why we should want each
> change) in the individual change descriptions?

Agreed.  I'll ask again after the next re-roll.

> > 1. Is it okay to use this kind of adaptive error handling (calling
> > 'die' in some places and returning error in other places), or should
> > it be more uniform?
> 
> 'die' gets used in two ways (well, one way really):
> 
>  - to say "there is no sane way to recover from this failure".  For
>    example, xmalloc dies if even after trying to free up memory,
>    malloc still could not satisfy the request.
> 
>  - to say "so far we've been too lazy to implement recovery from
>    this failure".  Or "while we *could* recover from this failure, no
>    one has needed it, so let's not --- that code would just bitrot."
> 
> Therefore a mixture of 'die' and 'return error' seems inevitable.  The
> dangerous mixtures to avoid are those likely to trip up callers (e.g.,
> if all code paths 'return error' except one edge case).

My thoughts precisely.  I was worried about what would happen in
future when Git is completely lib'ified, but I suppose it makes little
sense to think about that now.

> > 2. In 11/11, I've used cmd_revert and cmd_rerere.  This is highly
> > inelegant, mainly because of the command-line argument parsing
> > overhead.  Re-implementing it using more low-level functions doesn't
> > seem to be the way to go either: for example, 'reset --hard' has some
> > additional logic of writing HEAD and ORIG_HEAD, which I don't want to
> > duplicate.  Should I work on reworking parts of 'rerere.c' and
> > 'revert.c', or is there some other way?
> 
> See "git log --grep=libify" for examples.  Isn't rerere already
> libified?  Ah, you need "rerere clear" --- I think a rerere_clear
> function alongside rerere_forget et al would make sense.

Done in [1].

> More generally, it should be feasible to expose a nice, simple API for
> any functionality you need (with params struct if necessary, etc).
> That's how many of the current APIs (revision walking, diffcore, ...)
> came about.

I see.  Okay, I'll see if it makes sense to craft an API for rebase.

> > 3. From the format of the TODO and DONE files, one more thing should
> > be clear- I'm trying to stick to a slight variation of the 'rebase -i'
> > format.  This part will go into the sequencer.  Then I'll use a
> > cherry-pick specific file to keep the command-line options.  Yes, I'm
> > trying to work on Daniel's idea [3] from the very start.  Is this a
> > good idea?
> 
> This is still bouncing in my head.  I think I like it --- is the idea
> that some day you could put commands like
> 
> 	am topic.mbox
> 
> in your insn sheet, or do nested rebases with a --force-nested option?
> That does sound useful.  How would one request "skip to the next
> operation in the outer rebase" on the command line?  This is starting
> to feel like a debugger.

I'll respond to this later in the thread, since Daniel has already
said something.  I just need help with crafting a nice instruction
sheet now -- please join the discussion at [2].

> > 4. I have a feeling that I've broken translation strings.  Is there a
> > README, plus a bunch of tests I can run to make sure that I've not
> > broken anything?
> 
> If you put "GETTEXT_POISON = YesPlease" in your config.mak, the
> translations will be translated to gibberish when the GIT_GETTEXT_POISON
> envvar is set, so you can use the test suite as a sanity check.
> "make pot" can be used to get the translation template that
> translators will see.
> 
> As for a readme explaining how to use _, N_, and Q_, yes, I think that
> would be useful.  I think Ævar's series has something like that (but
> targetted at translators) later on; it might make sense to prod him or
> me for a simpler explanation can be merged immediately.  Until then,
> there is "git log gettext.h".

Thanks!  Someone should really document this whole translations thing.

-- Ram

[1]: http://article.gmane.org/gmane.comp.version-control.git/171314
[2]: http://thread.gmane.org/gmane.comp.version-control.git/171255/focus=171307