29.2.6 Moving over Balanced Expressions

Here are several functions concerned with balanced-parenthesis expressions (also called sexps in connection with moving across them in Emacs). The syntax table controls how these functions interpret various characters; see Syntax Tables. See Parsing Expressions, for lower-level primitives for scanning sexps or parts of sexps. For user-level commands, see Commands for Editing with Parentheses in The GNU Emacs Manual.

Command: forward-list &optional arg

This function moves forward across arg (default 1) balanced groups of parentheses. (Other syntactic entities such as words or paired string quotes are ignored.)

Command: backward-list &optional arg

This function moves backward across arg (default 1) balanced groups of parentheses. (Other syntactic entities such as words or paired string quotes are ignored.)

Command: up-list &optional arg

This function moves forward out of arg (default 1) levels of parentheses. A negative argument means move backward but still to a less deep spot.

Command: down-list &optional arg

This function moves forward into arg (default 1) levels of parentheses. A negative argument means move backward but still go deeper in parentheses (-arg levels).

Command: forward-sexp &optional arg

This function moves forward across arg (default 1) balanced expressions. Balanced expressions include both those delimited by parentheses and other kinds, such as words and string constants. See Parsing Expressions. For example,

---------- Buffer: foo ----------
(concat∗ "foo " (car x) y z)
---------- Buffer: foo ----------

(forward-sexp 3)
     ⇒ nil

---------- Buffer: foo ----------
(concat "foo " (car x) y∗ z)
---------- Buffer: foo ----------

Command: backward-sexp &optional arg

This function moves backward across arg (default 1) balanced expressions.

Command: beginning-of-defun &optional arg

This function moves back to the argth beginning of a defun. If arg is negative, this actually moves forward, but it still moves to the beginning of a defun, not to the end of one. arg defaults to 1.

Command: end-of-defun &optional arg

This function moves forward to the argth end of a defun. If arg is negative, this actually moves backward, but it still moves to the end of a defun, not to the beginning of one. arg defaults to 1.

User Option: defun-prompt-regexp

If non-nil, this buffer-local variable holds a regular expression that specifies what text can appear before the open-parenthesis that starts a defun. That is to say, a defun begins on a line that starts with a match for this regular expression, followed by a character with open-parenthesis syntax.

User Option: open-paren-in-column-0-is-defun-start

If this variable’s value is non-nil, an open parenthesis in column 0 is considered to be the start of a defun. If it is nil, an open parenthesis in column 0 has no special meaning. The default is t.

Variable: beginning-of-defun-function

If non-nil, this variable holds a function for finding the beginning of a defun. The function beginning-of-defun calls this function instead of using its normal method, passing it its optional argument. If the argument is non-nil, the function should move back by that many functions, like beginning-of-defun does.

Variable: end-of-defun-function

If non-nil, this variable holds a function for finding the end of a defun. The function end-of-defun calls this function instead of using its normal method.