Re: Call Me Gitless

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 19, 2008, 07:25 UTC
Message-ID: <7vbpzph3fx.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <alpine.LNX.1.00.0808181628420.19665@iabervon.org>

Daniel Barkalow <barkalow@iabervon.org> writes:

> .... For most systems, "diff" without options is a preview of 
> what would be in the patch if you were to commit; "git diff", on the other 
> hand, shows what would be left out of the patch.

That is true, but I also think that is because (1) on other systems, you cannot even choose to select changes to "leave out of the patch", so they have no option other than showing "what could be committed", and (2) by definition active use of index means that you are staging incrementally, and it is natural to expect you to want to view "changes since the last staging" much more often than "what would be committed" when you are staging incrementally, so the current default is the _right_ one.

So I'd say the below is a faulty argument:

> ...  So, even given that 
> people understand the meaning of the index, they can fail to understand 
> what "diff" will tell them.

If they understand "the meaning of the index", not just as literal reading of the manual page "it is a staging area to prepare for the next commit", but including the reason why there is a "staging area" and how it is to be used, they would reach the conclusion that "diff by default will show the leftover from incremental staging and it is the right thing".

> ... And diff is a bit unhelpful in that it 
> generates headers as for "diff -r a b", regardless of what the things are.

We have a separate thread on this now ;-)

Show 15 quoted lines

>> (2) Some concepts in git are different from what they are used to, without
>>     any good reason.  IOW, the concepts have room for improvement, and our
>>     UI is based on these faulty concepts.
>> 
>> (3) Some concepts in git may be exactly the same with other systems, yet
>>     our UI may operate differently from them without any good reason.
>> 
>> I'd be surprised if there is _no_ UI element that falls into the latter
>> two categories, but obviously I would not be able to list examples.  If I
>> could, they instead would have long been fixed already.
>
> You've got to include the class of "The concepts in git are exactly the 
> same as with other systems (although git also has additional concepts), 
> and commands from other systems do not do the same thing in git (with or 
> without good reason)."

Isn't it the same as (3)?

> E.g., git has a working directory, and git has a committed state, and CVS 
> has both of these, and "cvs diff" compares the working directory with the 
> committed state, but "git diff" does a different operation.

Ah, Ok, that is not the same as (3), but "although git has more" makes it totally different.

Your example sounds like comparing a car and a motorcycle. Yes they both share two tyres, but the former having two more tyres makes the driving technique of the whole thing quite different, doesn't it?