Re: [RFC] caar/cadr/cdar/cddr

[Paul Eggert]

On 07/12/2012 09:26 AM, Dmitry Antipov wrote:
> These are widely used

How widely?  I've always been leery about those
functions, myself.  Since this is a performance
improvement, how much does performance improve?

Quite possibly they're a win in the C implementation,
but I'm not sure they're worth adding bytecodes for.
We might want to save bytecodes for something more
important.

Assuming they're needed, I vote for a clean
implementation of Fcaar etc. rather than tricky
ones involving loops.  Especially since the tricky
loops are wrong and will infinite-loop in some
cases.