Class NilExpression
Object
NilExpression
- All Implemented Interfaces:
Serializable
,Expression
Placeholder class used to represent a NIL expression, evaluates to
null
. This placeholder class allows data
structures to avoid the use of null
. Please note that Expression.NIL
is not considered a Literal with
value null
(since the literal may have its value changed).- Author:
- Jody Garnett (Refractions Research, Inc.), Martin Desruisseaux (Geomatys)
- See Also:
-
Field Summary
Fields inherited from interface Expression
NIL
-
Method Summary
-
Method Details
-
accept
Accepts a visitor.- Specified by:
accept
in interfaceExpression
-
evaluate
Returnsnull
.- Specified by:
evaluate
in interfaceExpression
- Returns:
- computed value
-
evaluate
Returnsnull
.- Specified by:
evaluate
in interfaceExpression
- Type Parameters:
T
- The type of the returned object.- Parameters:
object
- The object to evaluate the expression against.context
- The type of the resulting value of the expression.- Returns:
- Evaluates the given expression based on the content of the given object an an instance of
context
.
-
toString
Returns a string representation of this expression.
-