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From:   Junio C Hamano <gitster@pobox.com>
To:     Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc:     Dennis Kaarsemaker <dennis@kaarsemaker.net>, git@vger.kernel.org
Subject: Re: [PATCH 2/2] difftool: add a feature flag for the builtin vs scripted version
References: <cover.1479834051.git.johannes.schindelin@gmx.de>
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Date:   Wed, 23 Nov 2016 10:18:56 -0800
In-Reply-To: <xmqqh96ym6x6.fsf@gitster.mtv.corp.google.com> (Junio C. Hamano's
        message of "Wed, 23 Nov 2016 09:40:05 -0800")
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Junio C Hamano <gitster@pobox.com> writes:

> Can't you route the control upon seeing "git difftool" to your
> experimental "C" difftool and check the configuration there?  Then
> you can decide to run_command() a non-builtin one depending what the
> configuration says---that way, you would incur cost of spawning Perl
> only when you need it, no?

FWIW, the approach taken by 73c2779f42 ("builtin-am: implement
skeletal builtin am", 2015-08-04) is what I had in mind when I wrote
the above.