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| author | Stefan Monnier <monnier@iro.umontreal.ca> | 2006-07-25 18:06:13 +0000 |
|---|---|---|
| committer | Stefan Monnier <monnier@iro.umontreal.ca> | 2006-07-25 18:06:13 +0000 |
| commit | 49c7d1acf058d2509b6311dda0e026dbb7990478 (patch) | |
| tree | 84b3db51d04ac0171593298f39fcf6fb3fc21190 /lisp/tabify.el | |
| parent | 94b392396335ef8b68c6b9e1405b73e472388a21 (diff) | |
| download | emacs-49c7d1acf058d2509b6311dda0e026dbb7990478.tar.gz | |
(tabify-regexp): Use more specific regexps.
(tabify): Avoid modifying the buffer unnecessarily.
Diffstat (limited to 'lisp/tabify.el')
| -rw-r--r-- | lisp/tabify.el | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/lisp/tabify.el b/lisp/tabify.el index 6e12270bf47..de37f281eda 100644 --- a/lisp/tabify.el +++ b/lisp/tabify.el @@ -50,10 +50,10 @@ The variable `tab-width' controls the spacing of tab stops." (delete-region tab-beg (point)) (indent-to column)))))) -(defvar tabify-regexp "[ \t][ \t]+" +(defvar tabify-regexp " [ \t]+" "Regexp matching whitespace that tabify should consider. -Usually this will be \"[ \\t][ \\t]+\" to match two or more spaces or tabs. -\"^[ \\t]+\" is also useful, for tabifying only initial whitespace.") +Usually this will be \" [ \\t]+\" to match two or more spaces or tabs. +\"^\\t* [ \\t]+\" is also useful, for tabifying only initial whitespace.") ;;;###autoload (defun tabify (start end) @@ -72,13 +72,24 @@ The variable `tab-width' controls the spacing of tab stops." (beginning-of-line) (narrow-to-region (point) end) (goto-char start) - (while (re-search-forward tabify-regexp nil t) - (let ((column (current-column)) - (indent-tabs-mode t)) - (delete-region (match-beginning 0) (point)) - (indent-to column)))))) + (let ((indent-tabs-mode t)) + (while (re-search-forward tabify-regexp nil t) + ;; The region between (match-beginning 0) and (match-end 0) is just + ;; spacing which we want to adjust to use TABs where possible. + (let ((end-col (current-column)) + (beg-col (save-excursion (goto-char (match-beginning 0)) + (skip-chars-forward "\t") + (current-column)))) + (if (= (/ end-col tab-width) (/ beg-col tab-width)) + ;; The spacing (after some leading TABs which we wouldn't + ;; want to touch anyway) does not straddle a TAB boundary, + ;; so it neither contains a TAB, nor will we be able to use + ;; a TAB here anyway: there's nothing to do. + nil + (delete-region (match-beginning 0) (point)) + (indent-to end-col)))))))) (provide 'tabify) -;;; arch-tag: c83893b1-e0cc-4e57-8a09-73fd03466416 +;; arch-tag: c83893b1-e0cc-4e57-8a09-73fd03466416 ;;; tabify.el ends here |