Re: [PATCH v1 1/3] Introduce config variable "diff.primer"

From: Keith Cascio <keith@cs.ucla.edu>
Date: Jan 25, 2009, 18:44 UTC
Message-ID: <alpine.GSO.2.00.0901251033160.12651@kiwi.cs.ucla.edu>
In-Reply-To: <alpine.DEB.1.00.0901251916010.14855@racer>

On Sun, 25 Jan 2009, Johannes Schindelin wrote:

> That would break existing scripts using "git diff" rather badly.  We already 
> did not allow something like "git config alias.diff ..." from changing the 
> behavior of "git diff", so I cannot find a reason why we should let 
> diff.primer (a misnomer BTW) override the behavior.

I took special care to protect all core scripts from the effects. Quote from patch 1/3:

> Protect git-format-patch, git-apply,
> git-am, git-rebase, git-gui and gitk
> from inapplicable options.

I fact, by introducing the cpp macro DIFF_MACHINE_FRIENDLY() and the command-line options "--machine-friendly" and "--no-primer", I made such protection declarative. Don't you find it preferable that existing programs and scripts would explicitly declare their desire for machine-friendly output?

The name "primer" is open to discussion, of course. But I like it. From Merriam-Webster: primer n 1: a device for priming 2: material used in priming a surface prime vb 1: fill, load 2: to prepare for firing 3: to apply the first color, coating or preparation to <~ a wall>

Thanks for your input.  More input welcome.
                                    -- Keith