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ANSI Common Lisp  7 Objects 7.7 Dictionary of Objects
| 7.7.11 slot-makunbound |
Function |
- Syntax:
-
slot-makunbound
instance slot-name
 instance
- Arguments and Values:
-
instance -- instance.
Slot-name - a symbol.
- Description:
-
The function slot-makunbound restores a slot
of the name slot-name in an instance to
the unbound state.
- Exceptional Situations:
-
If no slot of the name slot-name exists in the
instance, slot-missing is called as follows:
(slot-missing (class-of instance)
instance
slot-name
'slot-makunbound)
(Any values returned by slot-missing in this case are
ignored by slot-makunbound.)
The specific behavior depends on instance's metaclass.
An error is never signaled if instance has metaclass standard-class.
An error is always signaled if instance has metaclass built-in-class.
The consequences are undefined if instance has any other metaclass--an error
might or might not be signaled in this situation. Note in particular that the behavior
for conditions and structures is not specified.
- See Also:
-
slot-boundp,
slot-missing
- Notes:
-
Although no implementation is required to do so, implementors are strongly encouraged to implement the function slot-makunbound using the function slot-makunbound-using-class described in the Metaobject Protocol.
- Allegro CL Implementation Details:
-
None.
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