On Thu, Dec 13, 2007 at 05:40:23PM +0000, Junio C Hamano wrote:
> Pierre Habouzit <madcoder@xxxxxxxxxx> writes:
>
> > In fact we have kind of the issue for every single optional argument out
> > there:
> >
> > $ git describe --abbrev HEAD
> > error: option `abbrev' expects a numerical value
> > [...]
> >
> > *ouch*
> >
> > So I believe that with optional arguments we must change the way we do
> > things, and that we _must_ enforce the argument to be sticked in that
> > case.
>
> I think "Must" is a bit too strong an expression.
>
> git describe --abbrev 7 HEAD
> git describe --abbrev HEAD
> git describe --abbrev=HEAD
> git describe --abbrev=7 HEAD
> git describe --abbrev
>
> The --abbrev parser in this case could be asked with this question: "You
> are on the command line. There is a token after you. Is it your
> parameter?".
I thought of that, but it's really convoluted and can definitely lead
to very subtle issues. The number of git commands with optional
arguments is quite low, mostly due to legacy, I don't expect _new_
commands to take optional arguments. I don't really like the ambiguity
it creates, and in some cases you just won't be able to disambiguate at
all. Here it looks nice because --abbrev takes an integer argument, and
it's likely that no branch nor reference names will be only made of
digits. Though for commands taking an optional string[0] argument this is
way more fishy.
*I* (and it's my opinion, maybe other don't see it that way) see the
parse-option module as a convenience given to people using the CLI UI in
an interactive shell. So it tries to achieve a good balance between
brevity and error detection. Here I think it's quite error prone and
gives almost no help to the user: if there is a gain to type git repack
-afd vs. git repack -a -f -d, I see no real gain in --abbrev 10 vs.
--abbrev=10.
[0] OTOH I'm not sure there will ever be optional arguments that
aren't integers in git, but I may be wrong.
--
·O· Pierre Habouzit
··O madcoder@xxxxxxxxxx
OOO http://www.madism.org
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