OVERRIDE operator
The OVERRIDE
operator creates a property that implements the selection of one of the values (polymorphic form).
Syntax
OVERRIDE expr1, ..., exprN
Description
The OVERRIDE
operator creates a property whose value will be the value of one of the properties specified in the operator. Selection is made among properties with a non-NULL
value. If multiple properties are non-NULL
, the value of the first of these properties is selected.
Parameters
-
expr1, ..., exprN
List of expressions whose values will determine the value of the property.
Examples
CLASS Group;
markup = DATA NUMERIC[8,2] (Group);
markup = DATA NUMERIC[8,2] (Book);
group = DATA Group (Book);
overMarkup (Book b) = OVERRIDE markup(b), markup(group(b));
notNullDate (INTEGER i) = OVERRIDE date(i), 2010_01_01;