[ Recorded Database | Reference Manual | Alphabetic Index ]
referenced_record(+DBRef, -Value)
Succeeds if Value is the Term recorded under the database reference DBRef.
- DBRef
- A database reference.
- Value
- An arbitrary term.
Description
The database reference DBRef must refer to a term that has previously
been recorded in the record database. Database references can be
obtained from the predicates recorda/3, recordz/3 and recorded/3.
Value is unified with a copy of the recorded term. Note that this
is the case even if the original database entry has been removed since
the database reference was obtained (logical update semantics).
Modes and Determinism
- referenced_record(+, -) is det
Exceptions
- (4) instantiation fault
- DBRef is not instantiated.
- (5) type error
- DBRef is neither a variable nor a database reference.
Examples
[eclipse]: recordz(beer, paulaner, Ref), referenced_record(Ref, X).
Ref = $&(dbref,"370gf3")
X = paulaner
yes.
[eclipse]: recorded(beer, _, Ref), referenced_record(Ref, X).
Ref = $&(dbref,"370gw3")
X = paulaner More? (;)
yes.
[eclipse]: recorded(beer, _, Ref), erase(Ref), referenced_record(Ref, X).
Ref = $&(dbref,"370gw3")
X = paulaner More? (;)
yes.
Error:
referenced_record(_, Value). (Error 4)
referenced_record(123, Value). (Error 5)
See Also
recorda / 3, recordz / 3, recorded / 3, erase / 1, referenced_record / 2