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(elisp)Skipping Characters

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Skipping Characters
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   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 Note: 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 the number of characters
     moved over.

     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.  Note: 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 is just like `skip-chars-forward'
     except for the direction of motion.

     The return value indicates the distance traveled.  It is an
     integer that is zero or less.