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| author | Michal Nazarewicz <mina86@mina86.com> | 2016-06-21 16:46:52 +0200 |
|---|---|---|
| committer | Michal Nazarewicz <mina86@mina86.com> | 2016-07-04 14:11:35 +0200 |
| commit | 1f8b9408085adc087f94c34db732573f6c76f62f (patch) | |
| tree | ce0cc0058cf54b9d47ddc5a207cebbcb6454f7a1 | |
| parent | 8b30c33e187b4921203306579c798416d80df3d4 (diff) | |
| download | emacs-1f8b9408085adc087f94c34db732573f6c76f62f.tar.gz | |
Simplify ‘delete-trailing-whitespace’ by not treating \n as whitespace
* 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.
| -rw-r--r-- | lisp/simple.el | 7 | ||||
| -rw-r--r-- | test/lisp/simple-tests.el | 3 |
2 files changed, 6 insertions, 4 deletions
diff --git a/lisp/simple.el b/lisp/simple.el index 3fa23ff9477..37f6d5000e9 100644 --- a/lisp/simple.el +++ b/lisp/simple.el @@ -607,9 +607,10 @@ buffer if the variable `delete-trailing-lines' is non-nil." (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 2722544446d..97b6c491629 100644 --- a/test/lisp/simple-tests.el +++ b/test/lisp/simple-tests.el @@ -235,7 +235,8 @@ (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 |