From: Linus Torvalds <torvalds@osdl.org>
Date: Thu, 19 May 2005 22:26:39 GMT
Subject: Re: [PATCH] Detect renames in diff family.
Message-ID: <Pine.LNX.4.58.0505191516350.2322@ppc970.osdl.org>
In-Reply-To: <7vll6ayjok.fsf@assigned-by-dhcp.cox.net>



On Thu, 19 May 2005, Junio C Hamano wrote:
> 
> We are talking about the Plumbing.  Thank you for reminding me,
> but sometimes people end up using the bare Plumbing.

There's a pretty simple and nice way to make it both useful and easy to do 
to arbitrary precision.

Think of the number following the -M as the mantissa.

So -M9 means 0.9 aka "90% match" (or "difference", depending on which way
you want to go), and in general -Mx would have the "10% increments" thing.

But since it's a fraction, you just give more precision by adding more 
numbers, and -M99 would be "99% match", while "-M02" would be "2% match"

Then it would be logical for a plain -M to be 100% match / 0% difference
(ie only show renames that are exact), since a "0% match" / 100%
difference is nonsensical.

Alternatively, we'd have -M (without any number) just default to 
something, and you'd give a separate number of how closely you want to 
mach things, ie

	# These all mean the same thing: (default) 20% difference
	git-diff-tree -M
	git-diff-tree -M --match=80
	git-diff-tree -M --differ=20

	# show only renames that are perfect matches.
	git-diff-tree -M --match=100

	# show _everything_ as a rename, except the
	# matching matrix means that we prefer better
	# matches over worse
	git-diff-tree -M --match=0

Hmm?

		Linus