slot-unbound
slot-unbound class instance slot-name → {result}*
slot-unbound (class t) instance slot-name
class—the class of the instance.
instance—the instance in which an attempt was made to read the unbound slot.
slot-name—the name of the unbound slot.
result—an object.
The generic function slot-unbound is called when an unbound slot is read in an instance whose metaclass is standard-class. The default method signals an error of type unbound-slot. The name slot of the unbound-slot condition is initialized to the name of the offending variable, and the instance slot of the unbound-slot condition is initialized to the offending instance.
The generic function slot-unbound is not intended to be called by programmers. Programmers may write methods for it. The function slot-unbound is called only Looks like metaobjects to me. -kmp 15-Jan-91
by \thefunction{slot-value-using-class} and thusindirectly by slot-value.
Per X3J13. -kmp 05-Oct-93
If \funref{slot-unbound} returns, its values will be treated as follows:
\beginlist
\item{\bull}
If the \param{operation} is \misc{setf} or \misc{slot-makunbound},
any \term{values} will be ignored by the caller.
\item{\bull}
If the \param{operation} is \misc{slot-value},
only the \term{primary value} will be used by the caller,
and all other values will be ignored.
\item{\bull}
If the \param{operation} is \misc{slot-boundp},
any \term{boolean equivalent} of the \term{primary value}
of the \term{method} might be is used,
and all other values will be ignored.
\endlistIf slot-unbound returns, only the primary value will be used by the caller, and all other values will be ignored.
None.
None.
slot-unbound signals an error of type unbound-slot.
An unbound slot may occur if no :initform form was specified for the slot and the slot value has not been set, or if slot-makunbound has been called on the slot.