32.14 Auto Filling

Auto Fill mode is a minor mode that fills lines automatically as text is inserted. This section describes the hook used by Auto Fill mode. For a description of functions that you can call explicitly to fill and justify existing text, see 32.11 Filling.

Auto Fill mode also enables the functions that change the margins and justification style to refill portions of the text. See section 32.12 Margins for Filling.

Variable: auto-fill-function

The value of this variable should be a function (of no arguments) to be called after self-inserting a character from the table auto-fill-chars. It may be nil, in which case nothing special is done in that case.

The value of auto-fill-function is do-auto-fill when Auto-Fill mode is enabled. That is a function whose sole purpose is to implement the usual strategy for breaking a line.

In older Emacs versions, this variable was named auto-fill-hook, but since it is not called with the standard convention for hooks, it was renamed to auto-fill-function in version 19.

Variable: normal-auto-fill-function

This variable specifies the function to use for auto-fill-function, if and when Auto Fill is turned on. Major modes can set buffer-local values for this variable to alter how Auto Fill works.

Variable: auto-fill-chars

A char table of characters which invoke auto-fill-function when self-inserted--space and newline in most language environments. They have an entry t in the table.