diff options
Diffstat (limited to 'lisp/emacs-lisp/subr-x.el')
| -rw-r--r-- | lisp/emacs-lisp/subr-x.el | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/lisp/emacs-lisp/subr-x.el b/lisp/emacs-lisp/subr-x.el index b79482fd4b3..dc046c3d76a 100644 --- a/lisp/emacs-lisp/subr-x.el +++ b/lisp/emacs-lisp/subr-x.el @@ -322,7 +322,7 @@ The boundaries that match REGEXP are included in the result." (push (substring string start-substring) result) (nreverse result)))) -(defun string-pad (string length &optional padding) +(defun string-pad (string length &optional padding start) "Pad STRING to LENGTH using PADDING. If PADDING is nil, the space character is used. If not nil, it should be a character. @@ -330,16 +330,18 @@ should be a character. If STRING is longer than the absolute value of LENGTH, no padding is done. -If LENGTH is positive, the padding is done to the end of the -string, and if it's negative, padding is done to the start of the +If START is nil (or not present), the padding is done to the end +of the string, and non-nil, padding is done to the start of the string." - (let ((pad-length (- (abs length) (length string)))) + (unless (natnump length) + (signal 'wrong-type-argument (list 'natnump length))) + (let ((pad-length (- length (length string)))) (if (< pad-length 0) string - (concat (and (< length 0) + (concat (and start (make-string pad-length (or padding ?\s))) string - (and (> length 0) + (and (not start) (make-string pad-length (or padding ?\s))))))) (defun string-chop-newline (string) |