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Re: Easy to add with push but not to the end of a list
From: |
Emanuel Berg |
Subject: |
Re: Easy to add with push but not to the end of a list |
Date: |
Tue, 06 Dec 2022 03:40:02 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) |
Michael Heerdegen wrote:
> What happens if you compile a file with these contents
> for example?
>
> (defun test ()
> (let ((l (list 1 2)))
> (push-last 2 l)
> l))
Okay, this then?
;;; -*- lexical-binding: t -*-
;;
;; this file:
;; https://dataswamp.org/~incal/emacs-init/list.el
(defmacro push-last (elem lst)
"Push ELEM to be the last element of LST.
Beware that this is O(n) while `push' is O(1)."
`(if (and (symbolp ,lst)
(not (symbol-value ,lst)) )
(setq ,lst (list ,elem))
(nconc ,lst (list ,elem)) ))
>> Here is the `push' macro - TBH, I don't know what most of
>> that means ...
>
> That supports generalized variables; you don't need to do
> that (unless you want to).
Just wonder why mine looks so different ...
--
underground experts united
https://dataswamp.org/~incal
- Re: Easy to add with push but not to the end of a list, (continued)
- Re: Easy to add with push but not to the end of a list, Michael Heerdegen, 2022/12/05
- Re: Easy to add with push but not to the end of a list, Emanuel Berg, 2022/12/05
- Re: Easy to add with push but not to the end of a list, Michael Heerdegen, 2022/12/05
- Re: Easy to add with push but not to the end of a list, Emanuel Berg, 2022/12/06
- Re: Easy to add with push but not to the end of a list, Michael Heerdegen, 2022/12/06
- Re: Easy to add with push but not to the end of a list, Emanuel Berg, 2022/12/06
- Re: Easy to add with push but not to the end of a list, Michael Heerdegen, 2022/12/08
- Re: Easy to add with push but not to the end of a list, Emanuel Berg, 2022/12/29
- Re: Easy to add with push but not to the end of a list, Michael Heerdegen, 2022/12/31
- Re: Easy to add with push but not to the end of a list, Emanuel Berg, 2022/12/31
- Re: Easy to add with push but not to the end of a list,
Emanuel Berg <=
- Re: Easy to add with push but not to the end of a list, Stefan Monnier, 2022/12/06
- Re: Easy to add with push but not to the end of a list, Michael Heerdegen, 2022/12/06