From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 12 Aug 2009 20:30:25 GMT
Subject: Re: [PATCH 5/8] Add a config option for remotes to specify a foreign vcs
Message-ID: <7vocqkydum.fsf@alter.siamese.dyndns.org>
In-Reply-To: <m363ctpedr.fsf@localhost.localdomain>

Jakub Narebski <jnareb@gmail.com> writes:

> Jeff King <peff@peff.net> writes:
>
>>   1. Is there some other syntax that _doesn't_ have this breakage
>>      but that similarly helps the "vast majority of Git users".
>
> Well, proposed possible syntax was:
> 1. <vcs>:<repository location>
> ...
> 2. <vcs>::<repository location>
> ...
> 3. <vcs>+<repository location>
>
>    e.g.
>
>      svn+http://svn.example.com/project
>
>    but
>
>      http+svn://svn.example.com/project
>      svn+path/to/repo

I do not think these are valid examples to demonstrate that 3 is bad.

We do not have (and we will not create) "http+svn://" native transport, so
the former can only mean "Feed 'svn://svn.example.com/project' to the vcs
helper whose name is 'http'".  Similarly I do not see any way to read the
latter other than "Feed 'path/to/repo' to 'svn' vcs helper".

We do have a pair of synonyms "git+ssh://foo" and "ssh+git://bar" that
could make the use of '+' ambiguous.  They could be feeding 'ssh://foo'
and 'git://bar' to 'git' and 'ssh' vcs helpers respectively, but

 (1) they are not even advertised in Documentation/ anywhere as far as I
     can see; and

 (2) these are the only two existing ones that are misdesigned, and we can
     easily special case them to keep backward compatibility.

Double-colon (your 2) is also workable.  It probably is slightly better
than plus because it does not have to grandfather "git+ssh" and "ssh+git"
and that would be beneficial for requiring less complexity in both code
(i.e. special case logic) and more importantly in mental burden to the end
users (i.e. '::' would stand out more than '+' and clearly different from
traditional git URLs in all cases).

As Jeff said (your 1.), a single colon ':' has a rather bad ambiguity
between <vcs> and hostname part in the existing scp-style repository
naming.