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[Emacs-diffs] master f9ff60e: Improve regexp advice again, and unchain r
From: |
Paul Eggert |
Subject: |
[Emacs-diffs] master f9ff60e: Improve regexp advice again, and unchain ranges |
Date: |
Tue, 2 Apr 2019 18:01:39 -0400 (EDT) |
branch: master
commit f9ff60e0d7288e30cdbd1e43225059f1374441f1
Author: Paul Eggert <address@hidden>
Commit: Paul Eggert <address@hidden>
Improve regexp advice again, and unchain ranges
* doc/lispref/searching.texi (Regexp Special):
Mention char classes earlier, in a more-logical place.
Advise sticking to ASCII letters and digits in ranges.
Reword negative advice to make it clearer that it’s negative.
* lisp/files.el (make-auto-save-file-name):
* lisp/gnus/message.el (message-mailer-swallows-blank-line):
* lisp/gnus/nndoc.el (nndoc-lanl-gov-announce-type-p)
(nndoc-generate-lanl-gov-head):
* lisp/org/org-eshell.el (org-eshell-open):
* lisp/org/org.el (org-deadline-time-hour-regexp)
(org-scheduled-time-hour-regexp):
* lisp/progmodes/bat-mode.el (bat-font-lock-keywords):
* lisp/progmodes/bug-reference.el (bug-reference-bug-regexp):
* lisp/textmodes/less-css-mode.el (less-css-font-lock-keywords):
* lisp/vc/vc-cvs.el (vc-cvs-valid-symbolic-tag-name-p):
* lisp/vc/vc-svn.el (vc-svn-valid-symbolic-tag-name-p):
Avoid attempts to chain ranges, as this can be confusing.
For example, instead of [0-9-_.], use [0-9_.-].
---
doc/lispref/searching.texi | 52 +++++++++++++++++++++++++----------------
lisp/files.el | 2 +-
lisp/gnus/message.el | 2 +-
lisp/gnus/nndoc.el | 4 ++--
lisp/org/org-eshell.el | 2 +-
lisp/org/org.el | 4 ++--
lisp/progmodes/bat-mode.el | 2 +-
lisp/progmodes/bug-reference.el | 2 +-
lisp/textmodes/less-css-mode.el | 4 ++--
lisp/vc/vc-cvs.el | 2 +-
lisp/vc/vc-svn.el | 2 +-
11 files changed, 45 insertions(+), 33 deletions(-)
diff --git a/doc/lispref/searching.texi b/doc/lispref/searching.texi
index 72ee923..8775254 100644
--- a/doc/lispref/searching.texi
+++ b/doc/lispref/searching.texi
@@ -395,9 +395,18 @@ or @samp{$}, @samp{%} or period. However, the ending
character of one
range should not be the starting point of another one; for example,
@samp{[a-m-z]} should be avoided.
+A character alternative can also specify named character classes
+(@pxref{Char Classes}). This is a POSIX feature. For example,
address@hidden:ascii:]]} matches any @acronym{ASCII} character.
+Using a character class is equivalent to mentioning each of the
+characters in that class; but the latter is not feasible in practice,
+since some classes include thousands of different characters.
+A character class should not appear as the lower or upper bound
+of a range.
+
The usual regexp special characters are not special inside a
character alternative. A completely different set of characters is
-special inside character alternatives: @samp{]}, @samp{-} and @samp{^}.
+special: @samp{]}, @samp{-} and @samp{^}.
To include @samp{]} in a character alternative, put it at the
beginning. To include @samp{^}, put it anywhere but at the beginning.
To include @samp{-}, put it at the end. Thus, @samp{[]^-]} matches
@@ -430,33 +439,36 @@ matches only @samp{/} rather than the likely-intended
four characters.
@end enumerate
Some kinds of character alternatives are not the best style even
-though they are standardized by POSIX and are portable. They include:
+though they have a well-defined meaning in Emacs. They include:
@enumerate
@item
-A character alternative can include duplicates. For example,
address@hidden is less clear than @samp{[XYa-z]}.
+Although a range's bound can be almost any character, it is better
+style to stay within natural sequences of ASCII letters and digits
+because most people have not memorized character code tables.
+For example, @samp{[.-9]} is less clear than @samp{[./0-9]},
+and @samp{[`-~]} is less clear than @address@hidden|@}~]}.
+Unicode character escapes can help here; for example, for most programmers
address@hidden is less clear than @samp{[\u0E01-\u0E3A\u0E3F-\u0E5B]}.
@item
-A range can denote just one, two, or three characters. For example,
address@hidden(-(]} is less clear than @samp{[(]}, @samp{[*-+]} is less clear
-than @samp{[*+]}, and @samp{[*-,]} is less clear than @samp{[*+,]}.
+Although a character alternative can include duplicates, it is better
+style to avoid them. For example, @samp{[XYa-yYb-zX]} is less clear
+than @samp{[XYa-z]}.
@item
-A @samp{-} also appear at the beginning of a character alternative, or
-as the upper bound of a range. For example, although @samp{[-a-z]} is
-valid, @samp{[a-z-]} is better style; and although @samp{[!--/]} is
-valid, @samp{[!-,/-]} is clearer.
address@hidden enumerate
+Although a range can denote just one, two, or three characters, it
+is simpler to list the characters. For example,
address@hidden is less clear than @samp{[a0]}, @samp{[i-j]} is less clear
+than @samp{[ij]}, and @samp{[i-k]} is less clear than @samp{[ijk]}.
-A character alternative can also specify named character classes
-(@pxref{Char Classes}). This is a POSIX feature. For example,
address@hidden:ascii:]]} matches any @acronym{ASCII} character.
-Using a character class is equivalent to mentioning each of the
-characters in that class; but the latter is not feasible in practice,
-since some classes include thousands of different characters.
-A character class should not appear as the lower or upper bound
-of a range.
address@hidden
+Although a @samp{-} can appear at the beginning of a character
+alternative or as the upper bound of a range, it is better style to
+put @samp{-} by itself at the end of a character alternative. For
+example, although @samp{[-a-z]} is valid, @samp{[a-z-]} is better
+style; and although @samp{[*--]} is valid, @samp{[*+,-]} is clearer.
address@hidden enumerate
@item @samp{[^ @dots{} ]}
@cindex @samp{^} in regexp
diff --git a/lisp/files.el b/lisp/files.el
index 77a194b..1dae575 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -6316,7 +6316,7 @@ See also `auto-save-file-name-p'."
;; We do this on all platforms, because even if we are not
;; running on DOS/Windows, the current directory may be on a
;; mounted VFAT filesystem, such as a USB memory stick.
- (while (string-match "[^A-Za-z0-9-_.~#+]" buffer-name limit)
+ (while (string-match "[^A-Za-z0-9_.~#+-]" buffer-name limit)
(let* ((character (aref buffer-name (match-beginning 0)))
(replacement
;; For multibyte characters, this will produce more than
diff --git a/lisp/gnus/message.el b/lisp/gnus/message.el
index dae4b0d..c8b6f0e 100644
--- a/lisp/gnus/message.el
+++ b/lisp/gnus/message.el
@@ -1288,7 +1288,7 @@ called and its result is inserted."
;; According to RFC 822 and its successors, the field name must
;; consist of printable US-ASCII characters other than colon,
;; i.e., decimal 33-56 and 59-126.
- '(looking-at "[ \t]\\|[][!\"#$%&'()*+,-./0-9;<=>address@hidden|}~]+:"))
+ '(looking-at "[ \t]\\|[][!\"#$%&'()*+,./0-9;<=>address@hidden|}~-]+:"))
"Set this non-nil if the system's mailer runs the header and body together.
\(This problem exists on Sunos 4 when sendmail is run in remote mode.)
The value should be an expression to test whether the problem will
diff --git a/lisp/gnus/nndoc.el b/lisp/gnus/nndoc.el
index 8f1217b..532ba11 100644
--- a/lisp/gnus/nndoc.el
+++ b/lisp/gnus/nndoc.el
@@ -701,7 +701,7 @@ from the document.")
(defun nndoc-lanl-gov-announce-type-p ()
(when (let ((case-fold-search nil))
- (re-search-forward "^\\\\\\\\\n\\(Paper\\( (\\*cross-listing\\*)\\)?:
[a-zA-Z-\\.]+/[0-9]+\\|arXiv:\\)" nil t))
+ (re-search-forward "^\\\\\\\\\n\\(Paper\\( (\\*cross-listing\\*)\\)?:
[a-zA-Z\\.-]+/[0-9]+\\|arXiv:\\)" nil t))
t))
(defun nndoc-transform-lanl-gov-announce (article)
@@ -732,7 +732,7 @@ from the document.")
(save-restriction
(narrow-to-region (car entry) (nth 1 entry))
(goto-char (point-min))
- (when (looking-at "^\\(Paper.*: \\|arXiv:\\)\\([0-9a-zA-Z-\\./]+\\)")
+ (when (looking-at "^\\(Paper.*: \\|arXiv:\\)\\([0-9a-zA-Z\\./-]+\\)")
(setq subject (concat " (" (match-string 2) ")"))
(when (re-search-forward "^From: \\(.*\\)" nil t)
(setq from (concat "<"
diff --git a/lisp/org/org-eshell.el b/lisp/org/org-eshell.el
index bb27d92..2251a1b 100644
--- a/lisp/org/org-eshell.el
+++ b/lisp/org/org-eshell.el
@@ -37,7 +37,7 @@
eshell buffer) or a command line prefixed by a buffer name
followed by a colon."
(let* ((buffer-and-command
- (if (string-match "\\([A-Za-z0-9-+*]+\\):\\(.*\\)" link)
+ (if (string-match "\\([A-Za-z0-9+*-]+\\):\\(.*\\)" link)
(list (match-string 1 link)
(match-string 2 link))
(list eshell-buffer-name link)))
diff --git a/lisp/org/org.el b/lisp/org/org.el
index bf7e305..ce6dd24 100644
--- a/lisp/org/org.el
+++ b/lisp/org/org.el
@@ -430,7 +430,7 @@ Matched keyword is in group 1.")
(defconst org-deadline-time-hour-regexp
(concat "\\<" org-deadline-string
- " *<\\([^>]+[0-9]\\{1,2\\}:[0-9]\\{2\\}[0-9-+:hdwmy \t.]*\\)>")
+ " *<\\([^>]+[0-9]\\{1,2\\}:[0-9]\\{2\\}[0-9+:hdwmy \t.-]*\\)>")
"Matches the DEADLINE keyword together with a time-and-hour stamp.")
(defconst org-deadline-line-regexp
@@ -446,7 +446,7 @@ Matched keyword is in group 1.")
(defconst org-scheduled-time-hour-regexp
(concat "\\<" org-scheduled-string
- " *<\\([^>]+[0-9]\\{1,2\\}:[0-9]\\{2\\}[0-9-+:hdwmy \t.]*\\)>")
+ " *<\\([^>]+[0-9]\\{1,2\\}:[0-9]\\{2\\}[0-9+:hdwmy \t.-]*\\)>")
"Matches the SCHEDULED keyword together with a time-and-hour stamp.")
(defconst org-closed-time-regexp
diff --git a/lisp/progmodes/bat-mode.el b/lisp/progmodes/bat-mode.el
index 6c85ff9..a8b002b 100644
--- a/lisp/progmodes/bat-mode.el
+++ b/lisp/progmodes/bat-mode.el
@@ -78,7 +78,7 @@
"goto" "gtr" "if" "in" "leq" "lss" "neq" "not" "start"))
(UNIX
'("bash" "cat" "cp" "fgrep" "grep" "ls" "sed" "sh" "mv" "rm")))
- `(("\\_<\\(call\\|goto\\)\\_>[ \t]+%?\\([A-Za-z0-9-_\\:.]+\\)%?"
+ `(("\\_<\\(call\\|goto\\)\\_>[ \t]+%?\\([A-Za-z0-9_\\:.-]+\\)%?"
(2 font-lock-constant-face t))
("^:[^:].*"
. 'bat-label-face)
diff --git a/lisp/progmodes/bug-reference.el b/lisp/progmodes/bug-reference.el
index 8baf748..759db1f 100644
--- a/lisp/progmodes/bug-reference.el
+++ b/lisp/progmodes/bug-reference.el
@@ -69,7 +69,7 @@ so that it is considered safe, see `enable-local-variables'.")
(get s 'bug-reference-url-format)))))
(defcustom bug-reference-bug-regexp
- "\\([Bb]ug ?#?\\|[Pp]atch ?#\\|RFE ?#\\|PR
[a-z-+]+/\\)\\([0-9]+\\(?:#[0-9]+\\)?\\)"
+ "\\([Bb]ug ?#?\\|[Pp]atch ?#\\|RFE ?#\\|PR
[a-z+-]+/\\)\\([0-9]+\\(?:#[0-9]+\\)?\\)"
"Regular expression matching bug references.
The second subexpression should match the bug reference (usually a number)."
:type 'string
diff --git a/lisp/textmodes/less-css-mode.el b/lisp/textmodes/less-css-mode.el
index b4c7f28..4077789 100644
--- a/lisp/textmodes/less-css-mode.el
+++ b/lisp/textmodes/less-css-mode.el
@@ -194,10 +194,10 @@ directory by default."
;; - custom faces.
(defconst less-css-font-lock-keywords
'(;; Variables
- ("@[a-z_-][a-z-_0-9]*" . font-lock-variable-name-face)
+ ("@[a-z_-][a-z_0-9-]*" . font-lock-variable-name-face)
("&" . font-lock-preprocessor-face)
;; Mixins
- ("\\(?:[ \t{;]\\|^\\)\\(\\.[a-z_-][a-z-_0-9]*\\)[ \t]*;" .
+ ("\\(?:[ \t{;]\\|^\\)\\(\\.[a-z_-][a-z_0-9-]*\\)[ \t]*;" .
(1 font-lock-keyword-face))))
(defvar less-css-mode-syntax-table
diff --git a/lisp/vc/vc-cvs.el b/lisp/vc/vc-cvs.el
index 3bbd0ed..626e190 100644
--- a/lisp/vc/vc-cvs.el
+++ b/lisp/vc/vc-cvs.el
@@ -1087,7 +1087,7 @@ CVS/Entries should only be accessed through this
function."
;; an uppercase or lowercase letter and can contain uppercase and
;; lowercase letters, digits, `-', and `_'.
(and (string-match "^[a-zA-Z]" tag)
- (not (string-match "[^a-z0-9A-Z-_]" tag))))
+ (not (string-match "[^a-z0-9A-Z_-]" tag))))
(defun vc-cvs-valid-revision-number-p (tag)
"Return non-nil if TAG is a valid revision number."
diff --git a/lisp/vc/vc-svn.el b/lisp/vc/vc-svn.el
index 618f03e..3c50c8f 100644
--- a/lisp/vc/vc-svn.el
+++ b/lisp/vc/vc-svn.el
@@ -759,7 +759,7 @@ Set file properties accordingly. If FILENAME is non-nil,
return its status."
;; an uppercase or lowercase letter and can contain uppercase and
;; lowercase letters, digits, `-', and `_'.
(and (string-match "^[a-zA-Z]" tag)
- (not (string-match "[^a-z0-9A-Z-_]" tag))))
+ (not (string-match "[^a-z0-9A-Z_-]" tag))))
(defun vc-svn-valid-revision-number-p (tag)
"Return non-nil if TAG is a valid revision number."
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- [Emacs-diffs] master f9ff60e: Improve regexp advice again, and unchain ranges,
Paul Eggert <=