From db3874b16192142f473d53e3b80213ad74d19eff Mon Sep 17 00:00:00 2001
From: "Basil L. Contovounesios" <contovob@tcd.ie>
Date: Tue, 10 Jul 2018 19:51:28 -0700
Subject: [PATCH] Refer to "proper lists" instead of "true lists"
* doc/lispref/lists.texi (Cons Cells, Building Lists):
* doc/lispref/sequences.texi (Vector Functions): Use the more
popular term "proper", rather than "true", to qualify nil-terminated
lists.
For discussion, see the following emacs-devel subthreads:
https://lists.gnu.org/archive/html/emacs-devel/2018-06/msg00112.html
https://lists.gnu.org/archive/html/emacs-devel/2018-06/msg00138.html
---
doc/lispref/lists.texi | 23 +++++++++++++----------
doc/lispref/sequences.texi | 2 +-
2 files changed, 14 insertions(+), 11 deletions(-)
diff --git a/doc/lispref/lists.texi b/doc/lispref/lists.texi
index 431f5fbbab2..e05633a881d 100644
--- a/doc/lispref/lists.texi
+++ b/doc/lispref/lists.texi
@@ -50,16 +50,19 @@ convention; at the level of cons cells, the @sc{car} and @sc{cdr}
slots have similar properties). Hence, the @sc{cdr} slot of each cons
cell in a list refers to the following cons cell.
+@cindex proper list
@cindex true list
Also by convention, the @sc{cdr} of the last cons cell in a list is
@code{nil}. We call such a @code{nil}-terminated structure a
-@dfn{true list}. In Emacs Lisp, the symbol @code{nil} is both a
-symbol and a list with no elements. For convenience, the symbol
-@code{nil} is considered to have @code{nil} as its @sc{cdr} (and also
-as its @sc{car}).
-
- Hence, the @sc{cdr} of a true list is always a true list. The
-@sc{cdr} of a nonempty true list is a true list containing all the
+@dfn{proper list}@footnote{It is sometimes also referred to as a
+@dfn{true list}, but we generally do not use this terminology in this
+manual.}. In Emacs Lisp, the symbol @code{nil} is both a symbol and a
+list with no elements. For convenience, the symbol @code{nil} is
+considered to have @code{nil} as its @sc{cdr} (and also as its
+@sc{car}).
+
+ Hence, the @sc{cdr} of a proper list is always a proper list. The
+@sc{cdr} of a nonempty proper list is a proper list containing all the
elements except the first.
@cindex dotted list
@@ -71,10 +74,10 @@ Pair Notation}). There is one other possibility: some cons cell's
@sc{cdr} could point to one of the previous cons cells in the list.
We call that structure a @dfn{circular list}.
- For some purposes, it does not matter whether a list is true,
+ For some purposes, it does not matter whether a list is proper,
circular or dotted. If a program doesn't look far enough down the
list to see the @sc{cdr} of the final cons cell, it won't care.
-However, some functions that operate on lists demand true lists and
+However, some functions that operate on lists demand proper lists and
signal errors if given a dotted list. Most functions that try to find
the end of a list enter infinite loops if given a circular list.
@@ -522,7 +525,7 @@ object. The final argument is not copied or converted; it becomes the
is itself a list, then its elements become in effect elements of the
result list. If the final element is not a list, the result is a
dotted list since its final @sc{cdr} is not @code{nil} as required
-in a true list.
+in a proper list (@pxref{Cons Cells}).
@end defun
Here is an example of using @code{append}:
diff --git a/doc/lispref/sequences.texi b/doc/lispref/sequences.texi
index 188a3451140..327de6eb86a 100644
--- a/doc/lispref/sequences.texi
+++ b/doc/lispref/sequences.texi
@@ -1355,7 +1355,7 @@ each initialized to @var{object}.
@defun vconcat &rest sequences
@cindex copying vectors
This function returns a new vector containing all the elements of
-@var{sequences}. The arguments @var{sequences} may be true lists,
+@var{sequences}. The arguments @var{sequences} may be proper lists,
vectors, strings or bool-vectors. If no @var{sequences} are given,
the empty vector is returned.
--
2.39.5