| | | change-class | |
|
| instance new-class
&key &allow-other-keys
=> changed-instance | [Generic Function] |
Purpose
Change the class of an instance to new-class.
Method signatures
:around
(instance standard-object)
(new-class standard-unit-class)
&key &allow-other-keys
=> instance
|
:around
(instance standard-object)
(new-class standard-unit-class)
&key &allow-other-keys
=> instance
|
:before
(instance standard-unit-instance)
(new-class standard-class)
&key &allow-other-keys
|
:after
(instance standard-unit-instance)
(new-class standard-unit-class)
&key &allow-other-keys
|
:after
(instance standard-object)
(new-class standard-unit-class)
&key &allow-other-keys
|
Package :gbbopen
Module :gbbopen-core
Arguments and values
| instance | A standard-object instance
| |
| new-class | A class designator | |
| changed-instance | A standard-object instance
|
Returns
The destructively modified instance.
Events
If instance is a unit instance, a
change-instance-class-event is signaled at the start of the
class-change process. If new-class is a unit class, an
instance-changed-class-event is signaled when the class change has been
completed.
The following events may also be signaled:
unlink-event
remove-instance-from-space-instance-event
link-event
update-nonlink-slot-event
add-instance-to-space-instance-event
Errors
The existing or supplied instance name of instance is
identical to the instance name of an existing unit instance of
new-class.
Description
When new-class is a unit class, an instance-name conflict with
an existing unit instance of new-class must be avoided. If
the old class of instance and new-class are both unit
classes that use the global instance-name counter, the old instance-name value
can be retained safetly. If new-class is a unit class with a
class-based counter, specifying a new instance-name value (using
next-class-instance-number) is recommended.
When the old class and new-class are both unit classes and no space-instances value is supplied to change-class, the changed instance remains on all space instances that allow new-class unit instances. In addition, instance is also added to all space instances defined as initial-space-instances for new-class. If a space-instances value is supplied, instance is removed from all space instances and then added to the supplied space instances.
See also
define-unit-class
next-class-instance-number
Example
Change the class of unit instance hyp from probable-hyp
to rejected-hyp:
> (change-class hyp 'rejected-hyp
:instance-name (next-class-instance-number 'rejected-hyp))
#<rejected-hyp 1409 (896 388) .68>
>
Note that the :instance-name initarg can be eliminated if both the old
and new classes for hyp are using the global instance-name counter.
The GBBopen Project
| | | change-class | |