GNU Emacs Lisp Reference Manual

27.2.7: Skipping Characters

The following two functions move point over a specified set of characters. For example, they are often used to skip whitespace. For related functions, see Motion and Syntax.

Function: skip-chars-forward character-set &optional limit

This function moves point in the current buffer forward, skipping over a given set of characters. It examines the character following point, then advances point if the character matches character-set. This continues until it reaches a character that does not match. The function returns nil.

The argument character-set is like the inside of a [...] in a regular expression except that ] is never special and \ quotes ^, - or \. Thus, "a-zA-Z" skips over all letters, stopping before the first nonletter, and "^a-zA-Z" skips nonletters stopping before the first letter. See Regular Expressions.

If limit is supplied (it must be a number or a marker), it specifies the maximum position in the buffer that point can be skipped to. Point will stop at or before limit.

In the following example, point is initially located directly before the T. After the form is evaluated, point is located at the end of that line (between the t of hat and the newline). The function skips all letters and spaces, but not newlines.

---------- Buffer: foo ----------
I read "-!-The cat in the hat
comes back" twice.
---------- Buffer: foo ----------
(skip-chars-forward "a-zA-Z ")
     => nil

---------- Buffer: foo ----------
I read "The cat in the hat-!-
comes back" twice.
---------- Buffer: foo ----------

Function: skip-chars-backward character-set &optional limit

This function moves point backward, skipping characters that match character-set, until limit. It just like skip-chars-forward except for the direction of motion.