Re: [RFD] Git glossary: 'branch' and 'head' description

From: Jakub Narebski <jnareb@gmail.com>
Date: May 21, 2006, 08:30 UTC
Message-ID: <e4p8e8$uqt$2@sea.gmane.org>
In-Reply-To: <87y7wyv72m.fsf@morpheus.hq.vtech>

David Kågedal wrote:

> Jakub Narebski <jnareb@gmail.com> writes:

[...]

Show 13 quoted lines

>> So from the user's point of view, 'branch' is simply _named line of
>> development_. Refer to topic and tracking branches.
> 
> But the definition of 'branch' in git is quite different from the
> definition in CVS or many other systems.  It CVS, each revision
> (commit) belongs to a branch, and the branch is a linear sequence of
> revisions, not a full DAG.  In git, a commit doesn't really "belong"
> in any specific branch.
> 
> So, while it makes sense to describe branches as "lines of
> development" in general terms, it is also important to note the
> specific meaning of 'branch' in the context of git; i.e. as the
> history of a single head commit.

We can always say that branch is 1-st parent linear history of head branch, up to unmarked but computable branching/fork/creation point, i.e.

  {i = 0..N: branch-head~i}

where N is the length of the branch.

BTW. HEAD~0 == HEAD, isn't it?

-- 
Jakub Narebski
Warsaw, Poland