libedit-preferred by default

Neil Conway <neilc@samurai.com> writes:

If both libedit and libreadline are available, we currently default to
linking against libreadline, unless the "--with-libedit-preferred"
configure option is used. Why do we default to preferring GNU readline
over libedit?

readline has much more functionality (eg, one thing I miss in libedit is
history search capability ... perhaps that exists in some versions but
it doesn't in Apple's).

libedit is clearly preferable for license reasons. You could make the
argument that libedit is perhaps less stable than readline (although I'm
not aware of any outstanding issues with it), but (a) we need to support
libedit anyway, due to Darwin and NetBSD (b) if there are any issues
with libedit, users can always specify "--without-libedit-preferred" (c)
those users with both libraries installed are presumably at least
somewhat satisfied with libedit.

(c) is not a very good argument because of the possibility that the user
never explicitly selected either library, it just got installed as part
of his default OS. Also, your argument cuts both ways: if the user is
on a platform where libedit is standard, and he went to the trouble of
installing readline, wouldn't he want us to use readline?

We have the switches in place to let users make a choice when they want
to. I think that if we change the default all we're likely to get is
complaints from people for whom the behavior changed unexpectedly.

regards, tom lane

On Mon, 2007-28-05 at 15:24 -0400, Tom Lane wrote:

readline has much more functionality

Fair enough, that's probably a good enough reason to leave things as
they are for now.

-Neil