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NNTP-Posting-Date: Sat, 10 Aug 2024 20:23:05 +0000
From: steve g <sgonedes1977@gmail.com>
Newsgroups: gnu.emacs.help
Subject: Re: TCO with named-let via macros
References: <m11q42e6zz.fsf@void.com> <8734oi5ksx.fsf@axel-reichert.de> <m1ttgxhkp3.fsf@void.com>
Date: Sat, 10 Aug 2024 16:22:54 -0400
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Richard Smith <null@void.com> writes:

> Axel - I know that elisp doesn't optimise if an expressed recursive
> function is tail-recursive.

actually the byte-compiler does do tail recursive optimizations.

> A practical work-around is an alterative approach using the looping
> built-in's like "dotimes" (?) - where a recursive approach would have
> minimalistic beauty.
> Regards, Rich S


check the elisp manual. it shows how to implement true tail recursion in
emacs.


(defun elisp-sum (args)
  (elisp-sum-aux args 0))

(defun elisp-sum-aux (args res)
  (if (null args)
      res
      (elisp-sum-aux (cdr args) (+ (car args) res))))


you can byte compile it. very simple.