6.4.19 The Operator *
This operator may only be used in the following ways:
record *
symbol
- This yields the record which only contains the attribute of record
whose name is symbol.
record1 *
record2
- This yields a record wich consists of all attributes of record1
and record2. If record1 and record2 have a common
attribute names, the corresponding attributes in the result record will
have the attribute values from record1, in contrast to the
operator
+
.
record *
list
- Her, list must be a list of symbols. This yields the record which
only contains the attributes of record whose names are in
list.
list1 *
list2
- This yields the intersection of the lists interpreted as
multi-sets; if an element is m times contained in list1 and
n times contained in list2, it will be
min(
m,
n)
times contained in the result.
number1 *
number2
- This yields the product of number1 and number2.