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 Filling.
Auto Fill mode also enables the functions that change the margins and justification style to refill portions of the text. See Margins.
The value of this buffer-local 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
do-auto-fillwhen Auto-Fill mode is enabled. That is a function whose sole purpose is to implement the usual strategy for breaking a line.
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.