The
define-action
macro adds a new action to the action list specified by
name-or-list
; this action will be executed according to the action-list's execution-function (see execute-actions) when executed. If the action-list specified by
name-or-list
does not exist, then this is handled according to the value of *handle-missing-action-list*.
name-or-list
is evaluated to give either a list UID (to be looked up in the global registry of lists) or an action list object.
action-name
is a UID (general lisp object, to be compared by
equalp
). It uniquely identifies this action within its list (as opposed to among all lists).
data specifies an object referring to data relevant to the action.
specs is a free-form list of ordering specifiers and extra keywords, used to control more details of how and when this action is executed.
Action-items are normally expected not to be redefined. If an action-item with that action-name already exists in the action-list (that is, one with an identifier
equalp
to the action-name), then the notification and subsequent handling of this attempt is controlled by the values in the list *handle-existing-action-in-action-list*. This is to prevent problems due to re-evaluating an action definition inappropriately. Notification and redefine behavior can be overridden by using the
:force
keyword argument. In this case, any required redefinition is performed unconditionally and without notification.
The following keywords are recognized in the specs argument:
The following element in
specs
is a UID.
:after
specifies that the action-item being defined must be run after the action-item named. If there is no action-item with a matching name, the restriction is ignored.
Like
:after
, but this action-item must be run before the one specified.
:after
and
:before
can be specified as many times as necessary to describe the ordering constraints of this action-item with respect to its neighbors.
Specifies that this action-item should be executed only once; after execution, it is disabled.
Specifies that this definition should override any previous definition of this action-item, rather than be subject to the value of *handle-existing-action-in-action-list*.
(define-action :network-startup "Reset decnet buffers"
'(decnet::reset-network-buffers
*net-buffers*)
:after "Reset core network"
:once))
LispWorks User Guide and Reference Manual - 21 Dec 2011