Re: [PATCH 12/19] tree-diff: remove special-case diff-emitting code for empty-tree cases

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 25, 2014, 22:07 UTC
Message-ID: <xmqqzjkej5ju.fsf@gitster.dls.corp.google.com>
In-Reply-To: <20140325092040.GA3777@mini.zxlink>

Kirill Smelkov <kirr@navytux.spb.ru> writes:

Show 10 quoted lines

> On Mon, Mar 24, 2014 at 02:18:10PM -0700, Junio C Hamano wrote:
>> Kirill Smelkov <kirr@mns.spb.ru> writes:
>> 
>> > via teaching tree_entry_pathcmp() how to compare empty tree descriptors:
>> 
>> Drop this line, as you explain the "pretend empty compares bigger
>> than anything else" idea later anyway?  This early part of the
>> proposed log message made me hiccup while reading it.
>
> Hmm, I was trying to show the big picture first and only then details...

The subject should be sufficient for the big picture. "OK, we are removing the special casing" is what we expect the reader to get. Then, this

>> > While walking trees, we iterate their entries from lowest to highest in
>> > sort order, so empty tree means all entries were already went over.

sets the background. "OK, the code walks two trees, both have sorted elements, in parallel." is what we want the reader to understand. Then the next part gives the idea of pretending that the empty-side always compare later than the non-empty side while doing that parallel walking (similar to "merge").

So, yes, I think it is a good presentation order to give big picture punch-line first on the subject, some background and then the solution.