Begins or adds to a function definition. Here is an example:

AddToFunc Move-or-Raise I Raise
 + M Move
 + D Lower

The function name is "Move-or-Raise", and it could be invoked from a menu or a mouse binding or key binding:

Mouse 1 TS A Move-or-Raise

The name must not contain embedded whitespace. No guarantees are made whether function names with embedded whitespace work or not. This behavior may also change in the future without further notice. The letter before the action tells what kind of action triggers the command which follows it. 'I' stands for "Immediate", and is executed as soon as the function is invoked. 'M' stands for "Motion", i.e. if the user starts moving the mouse. 'C' stands for "Click", i.e., if the user presses and releases the mouse button. 'H' stands for "Hold", i.e. if the user presses a mouse button and holds it down for more than ClickTime milliseconds. 'D' stands for "Double-click". The action 'I' causes an action to be performed on the button-press, if the function is invoked with prior knowledge of which window to act on.

There is a number of predefined symbols that are replaced by certain values if they appear on the command line. Please refer to the Command Expansion section for details.

Examples:

If you call

Key F10 R A Function MailFunction xmh "-font fixed"

and "MailFunction" is

AddToFunc MailFunction
 + I Next ($0) Iconify off
 + I Next (AcceptsFocus, $0) Focus
 + I None ($0) Exec exec $0 $1

Then the last line of the function becomes

 + I None (xmh) Exec exec xmh -font fixed

The expansion is performed as the function is executed, so you can use the same function with all sorts of different arguments. You could use

Key F11 R A Function MailFunction zmail "-bg pink"

in the same config, if you wanted. An example of using "$[w.id]" is:

AddToFunc PrintFunction
 + I Raise
 + I Exec xdpr -id $[w.id]

Note that "$$" is expanded to '$'.

Another example: bind right mouse button within the window button number 6 (this is a minimize button for the win95 theme) to iconify all windows of the same resource:

AddToFunc FuncIconifySameResource "I" All ($0) Iconify on
Mouse 3 6 A FuncIconifySameResource $[w.resource]