Emacs Lisp: skip-chars-forward vs re-search-forward
skip-chars-forward vs re-search-forward
Suppose you have a URL. Cursor is somewhere on the URL, or at the beginning of the URL or at the end of the URL. You want to find the beginning position and end position of the URL.
If you use
re-search-backward for whitespace, you have to consider if the URL is at the beginning of file with no character before it.
skip-chars-backward, you don't have to do this extra check.
;; compare skip-chars-forward vs re-search-forward (save-excursion (skip-chars-backward "^[:space:]") (setq xp1 (point)) (skip-chars-forward "^[:space:]") (setq xp2 (point))) (save-excursion (re-search-backward "[[:space:]]" nil 1) (setq xp1 (1- (point))) (re-search-forward "[[:space:]]" nil 1) (setq xp2 (1- (point))))