uk.ac.sheffield.jast.filter

Class NotFilter

java.lang.Object

uk.ac.sheffield.jast.filter.Filter

uk.ac.sheffield.jast.filter.NotFilter

public class NotFilter
extends Filter

NotFilter is a compound filter applying the logical-NOT of another filter. A NotFilter is a kind of Filter that represents the logical negation of another Filter. It accepts the logical complement of the other Filter, that is, everything rejected by the other Filter is accepted by this NotFilter, and vice-versa. When the not() method is invoked on any other kind of Filter, this creates and returns a new NotFilter, with the other Filter as its component.

NotFilter has an accept(Content) method that returns true, only if the component Filter returns false, when applied to the same Content node. Likewise, it returns false if the component Filter returns true. Using a NotFilter is the easiest way to construct a Filter accepting "everything but" some specified pattern.

Version:

2.5

Author:

Anthony J H Simons

Field Summary

Fields

Modifier and Type	Field and Description
private Filter	filter The filter whose complement is matched by this NotFilter.

Fields inherited from class uk.ac.sheffield.jast.filter.Filter

ALLCONTENT, NAMENODES, PARENTNODES, PROPERTYNODES, VALUENODES, XPATHNODES, XPATHTEXT

Constructor Summary

Constructors

Constructor and Description
NotFilter(Filter other) Creates an NotFilter accepting the logical complement of the other Filter.

Method Summary

Modifier and Type	Method and Description
boolean	accept(Content node) Reports whether a given Content node is accepted by this NotFilter.
protected AndFilter	andNodeFilter(NodeFilter other) Creates a Filter that is the logical-AND of this NotFilter and a NodeFilter.
Filter	not() Creates a Filter that is the logical NOT of this NotFilter.
java.lang.String	toString() Returns a pretty representation of this Filter.

Methods inherited from class uk.ac.sheffield.jast.filter.Filter

and, andIndexFilter, or, orNodeFilter

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

filter

private Filter filter

The filter whose complement is matched by this NotFilter.

Constructor Detail

NotFilter

public NotFilter(Filter other)

Creates an NotFilter accepting the logical complement of the other Filter. The complementary filter is stored in this NotFilter.

Parameters:

other - a Filter.

Method Detail

accept

public boolean accept(Content node)

Reports whether a given Content node is accepted by this NotFilter. Only accepts the node, if the stored complementary filter rejects the node; and rejects the node if the complementary filter accepts it.

Specified by:

accept in class Filter

Parameters:

node - a Content node.

Returns:

true, if the node is accepted, otherwise false.

not

public Filter not()

Creates a Filter that is the logical NOT of this NotFilter. The new Filter accepts Content that was rejected by this NotFilter. Returns the original complementary Filter, which was wrapped by this NotFilter. This is more efficient than constructing a new NotFilter.

Overrides:

not in class Filter

Returns:

a new Filter, the complement of this NotFilter.

andNodeFilter

protected AndFilter andNodeFilter(NodeFilter other)

Creates a Filter that is the logical-AND of this NotFilter and a NodeFilter. Returns a new AndFilter, which evaluates the NodeFilter before this NotFilter, for efficiency's sake.

Overrides:

andNodeFilter in class Filter

Parameters:

other - the other NodeFilter.

Returns:

a new Filter, a conjunction of this and the other Filter.

toString

public java.lang.String toString()

Returns a pretty representation of this Filter. Returns the name of this NotFilter, with brackets surrounding the nested Filter.

Overrides:

toString in class Filter