From: Mattias Engdegård <mattiase@acm.org>
Date: Sat, 25 Jan 2020 15:16:37 +0000 (+0100)
Subject: Moderate recommendation to escape '(' in doc strings
X-Git-Tag: emacs-27.0.90~94
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=2e9a153b26;p=emacs.git

Moderate recommendation to escape '(' in doc strings

Thanks to 57e2ca5c50 and related changes, opening brackets at the
leftmost column inside doc strings are no longer mistaken for the
start of a defun.

* doc/lispref/tips.texi (Documentation Tips): Clarify recommendation
and move it down the list.
* etc/NEWS: Announce.
---

diff --git a/doc/lispref/tips.texi b/doc/lispref/tips.texi
index 4395069fe24..0610f8029df 100644
--- a/doc/lispref/tips.texi
+++ b/doc/lispref/tips.texi
@@ -802,18 +802,6 @@ explicitly what constitutes truth.  The word ``return'' avoids
 starting the sentence with lower-case ``t'', which could be somewhat
 distracting.
 
-@item
-If a line in a documentation string begins with an open-parenthesis,
-write a backslash before the open-parenthesis, like this:
-
-@example
-The argument FOO can be either a number
-\(a buffer position) or a string (a file name).
-@end example
-
-This prevents the open-parenthesis from being treated as the start of a
-defun (@pxref{Defuns,, Defuns, emacs, The GNU Emacs Manual}).
-
 @item
 Write documentation strings in the active voice, not the passive, and in
 the present tense, not the future.  For instance, use ``Return a list
@@ -849,6 +837,21 @@ The documentation string for a variable that is a yes-or-no flag should
 start with words such as ``Non-nil means'', to make it clear that
 all non-@code{nil} values are equivalent and indicate explicitly what
 @code{nil} and non-@code{nil} mean.
+
+@item
+If a line in a documentation string begins with an open-parenthesis,
+consider writing a backslash before the open-parenthesis, like this:
+
+@example
+The argument FOO can be either a number
+\(a buffer position) or a string (a file name).
+@end example
+
+This avoids a bug in Emacs versions older than 27.1, where the
+@samp{(} was treated as the start of a defun
+(@pxref{Defuns,, Defuns, emacs, The GNU Emacs Manual}).
+If you do not anticipate anyone editing your code with older Emacs
+versions, there is no need for this work-around.
 @end itemize
 
 @node Comment Tips
diff --git a/etc/NEWS b/etc/NEWS
index 792851e5af5..433f1f76b80 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -3338,6 +3338,10 @@ versions.
 'forward-comment', 'scan-sexps', and 'forward-sexp' when parsing backward.
 The new variable 'comment-use-syntax-ppss' can be set to nil to recover
 the old behavior if needed.
+This also means that there is no longer any need to precede opening
+brackets at the start of a line inside documentation strings with a
+backslash, although there is no harm in doing so to make the code
+easier to edit with an older Emacs version.
 
 ---
 ** The 'server-name' and 'server-socket-dir' variables are set when a