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bug#23843: [PATCH 2/3] Simplify ‘delete-trailing-whitespace’ by not trea
From: |
Michal Nazarewicz |
Subject: |
bug#23843: [PATCH 2/3] Simplify ‘delete-trailing-whitespace’ by not treating \n as whitespace |
Date: |
Sat, 25 Jun 2016 00:14:44 +0200 |
* lisp/simple.el (delete-trailing-whitespace): Set newline’s character
syntax to non-whitespace so that ‘\s-’ regular expression does not match
it.
This simplifies the loop slightly since a simple ‘\s-+$’ can be used and
as a consequence ‘line-beginning-position’ function does not need to be
called any longer.
Furthermore, when newline has whitespace syntax, ‘\s-$’ regular
expression ends up matching empty lins since ‘\s-’ matches newline
characetr of proceeding line. This leads to needless loop iterations.
Since previous change to ‘delete-trailing-whitespace’ already introduced
‘with-syntax-table’, take advantage of it and also overwrite newline’s
character syntax.
---
lisp/simple.el | 7 ++++---
test/lisp/simple-tests.el | 3 ++-
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/lisp/simple.el b/lisp/simple.el
index ffedbfa..fbeef9d 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -607,9 +607,10 @@ delete-trailing-whitespace
(with-syntax-table (make-syntax-table (syntax-table))
;; Don't delete formfeeds, even if they are considered whitespace.
(modify-syntax-entry ?\f "_")
- (while (re-search-forward "\\s-$" end-marker t)
- (skip-syntax-backward "-" (line-beginning-position))
- (delete-region (point) (match-end 0))))
+ ;; Treating \n as non-whitespace makes things easier.
+ (modify-syntax-entry ?\n "_")
+ (while (re-search-forward "\\s-+$" end-marker t)
+ (delete-region (match-beginning 0) (match-end 0))))
;; Delete trailing empty lines.
(goto-char end-marker)
(when (and (not end)
diff --git a/test/lisp/simple-tests.el b/test/lisp/simple-tests.el
index 2722544..97b6c49 100644
--- a/test/lisp/simple-tests.el
+++ b/test/lisp/simple-tests.el
@@ -235,7 +235,8 @@ simple-test--transpositions
(insert " \f \n \f \f \n\nlast\n")
(delete-trailing-whitespace)
(should (string-equal (buffer-string) " \f\n \f \f\n\nlast\n"))
- (should (equal ?\s (char-syntax ?\f))))))
+ (should (equal ?\s (char-syntax ?\f)))
+ (should (equal ?\s (char-syntax ?\n))))))
;;; auto-boundary tests
--
2.8.0.rc3.226.g39d4020