From 5ead8c5f69b0a69bac4641d5003ee422d6b67038 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Mattias=20Engdeg=C3=A5rd?= Date: Thu, 27 Apr 2023 13:52:57 +0200 Subject: [PATCH] Clarify `nconc` behaviour for dotted lists (bug#63103) * doc/lispref/lists.texi (Rearrangement): Explicitly say that dotted lists are valid args to `nconc` and give an example. --- doc/lispref/lists.texi | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/doc/lispref/lists.texi b/doc/lispref/lists.texi index a509325854f..22a5f7f1239 100644 --- a/doc/lispref/lists.texi +++ b/doc/lispref/lists.texi @@ -1224,7 +1224,15 @@ x @end example However, the other arguments (all but the last) should be mutable -lists. +lists. They can be dotted lists, whose last @sc{cdr}s are then +replaced with the next argument: + +@example +@group +(nconc (cons 1 2) (cons 3 (cons 4 5)) 'z) + @result{} (1 3 4 . z) +@end group +@end example A common pitfall is to use a constant list as a non-last argument to @code{nconc}. If you do this, the resulting behavior is undefined -- 2.39.5