Class Null

java.lang.Object
  |
  +--Null
All Implemented Interfaces:
FILisable, java.io.Serializable

public class Null
extends java.lang.Object
implements java.io.Serializable, FILisable

The class `Null' represents a value of null in two circumstances:

  • When the problem part of a case explicitly specifies a null slot filler, the filler in the case is represented internally as an instance of Null (since representing it as null means that the case does not specify a filler for the slot).
  • When a variable is bound to null, its binding is represented internally as an instance of Null (since representing it as null means that the variable is unbound).

    See Also:
    Serialized Form

    Constructor Summary
    Null()
               
     
    Method Summary
     java.lang.String FILise(boolean HTML)
              Returns a string representing Null in FIL.
     
    Methods inherited from class java.lang.Object
    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
     

    Constructor Detail

    Null

    public Null()
    Method Detail

    FILise

    public java.lang.String FILise(boolean HTML)
    Returns a string representing Null in FIL.
    Specified by:
    FILise in interface FILisable
    Parameters:
    HTML - If true, the FIL will be augmented with HTML tags.
    Returns:
    A string representing Null in FIL.