GNU bug report logs - #34852
26.1; seq-intersection ignores nil as element

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From: "Basil L. Contovounesios" <contovob <at> tcd.ie>
To: Michael Heerdegen <michael_heerdegen <at> web.de>
Cc: Nicolas Petton <nicolas <at> petton.fr>, 34852 <at> debbugs.gnu.org, Stefan Monnier <monnier <at> iro.umontreal.ca>, "Miguel V. S. Frasson" <mvsfrasson <at> gmail.com>
Subject: bug#34852: 26.1; seq-intersection ignores nil as element
Date: Thu, 14 Mar 2019 17:02:22 +0000

Michael Heerdegen <michael_heerdegen <at> web.de> writes:

> "Basil L. Contovounesios" <contovob <at> tcd.ie> writes:
>
>> My first patch makes an analogous backward-compatible change using the
>> more efficient seq-position in place of seq-some.
>
> Why is it more efficient?  The implementations are more or less
> analogue, with the exception that seq-position additionally increments a
> counter.

Because seq-some involves an additional level of function indirection.
This is confirmed by profiling and the attached mini-benchmark, when run
as follows:

emacs -batch -f batch-byte-compile bench.el
emacs -script bench.elc

A call to seq-position is also less verbose than one to seq-some for the
purpose of finding an element of a sequence.

Having said that, the differences are obviously very small.

-- 
Basil

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