From: H. Peter Anvin <hpa@zytor.com>
Date: Thu, 08 Dec 2005 22:02:05 GMT
Subject: Re: as promised, docs: git for the confused
Message-ID: <4398AD5D.7010101@zytor.com>
In-Reply-To: <7vk6efb6ib.fsf@assigned-by-dhcp.cox.net>

Junio C Hamano wrote:
> linux@horizon.com writes:
> 
> 
>>* Terminology - heads, branches, refs, and revisions
>>
>>(This is a supplement to what's already in "man git".)
>>
>>The most common object needed by git primitives is a tree.  Since a
>>commit points to a tree and a tag points to a commit, both of these are
>>acceptable "tree-ish" objects and can be used interchangeably.  Likewise,
>>a tag is "commit-ish" and can be used where a commit is required.
> 
> 
> I am unsure if we want to further confuse readers by saying
> this, but technically, "Likewise, a tag which is commit-ish can
> be used in place of commit".  Not all tags are necessarily
> commit-ish.  v2.6.11 tag is tree-ish but not commit-ish for
> example.  Typically, however, a tag is commit-ish.
> 

Saying they can be used interchangably is just plain wrong, however. 
It's not a bijective relation.

Something like:

 >> The most common object needed by git primitives is a tree.  Since a
 >> commit points and tags uniquely identify a tree, a commit or tag can
 >> be used anywhere a tree is expected.

 >> Likewise, most tags point to commits and can be used anywhere a
 >> commit is expected.

... might be better, and avoids the colloquialisms.

	-hpa