uk.ac.sheffield.jast.filter

Class NameSetFilter

java.lang.Object

uk.ac.sheffield.jast.filter.Filter

uk.ac.sheffield.jast.filter.MaskFilter

uk.ac.sheffield.jast.filter.NameSetFilter

public class NameSetFilter
extends MaskFilter

NameSetFilter is a simple filter for selecting nodes with names in a given set. A NameSetFilter accepts a subset of named nodes, whose names come from a set of reference names. Named nodes include Element and Attribute. The set of reference names may be provided as a String, in which the names are separated by a comma, a space, or a vertical bar '|'. The set may also be provided as a list of name tokens. NameSetFilter compares interned symbols by identity, for efficiency, and can either compare short names or long identifiers.

NameFilter has an accept(Content) method, which returns true, if the Content node is an acceptable named entity, and the node's name is in the set. Tested nodes are compared either using their short name, or their long identifier, depending on whether the reference names are short names or long identifiers (containing a colon ':'s separator. If at least one reference name contains a colon, all comparisons will be done using getIdentifier(), otherwise comparisons will be done using getName().

Version:

2.5

Author:

Anthony J H Simons

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.Map<java.lang.String,java.lang.Boolean>	nameSet The interned set of reference names.
private boolean	simple A flag indicating whether the reference names are simple names (true), or full identifiers (false) prefixed with a namespace identifier and colon.

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

mask

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

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

Constructor Summary

Constructors

Modifier	Constructor and Description
	NameSetFilter(java.util.List<java.lang.String> nameList) Creates a NameSetFilter selecting named nodes from a list of names.
	NameSetFilter(java.util.List<java.lang.String> nameList, int contentType) Creates a NameSetFilter selecting named nodes of a given content-type from a list of names.
private	NameSetFilter(NameSetFilter filter, int contentType) Secret constructor to copy a NameSetFilter but reset the type mask.
	NameSetFilter(java.lang.String nameRange) Creates a NameSetFilter selecting named nodes from an enumerated range.
	NameSetFilter(java.lang.String nameRange, int contentType) Creates a NameSetFilter selecting named nodes of a given content-type from an enumerated range.

Method Summary

Modifier and Type	Method and Description
boolean	accept(Content node) Reports whether a given Content node is accepted by this NameSetFilter.
protected NameSetFilter	andNodeFilter(NodeFilter other) Creates a Filter that is the conjunction of this NameSetFilter and a NodeFilter.
private boolean	matchName(Markup node) Reports whether a Markup node's name is contained within the name set.
private void	populate(java.util.List<java.lang.String> nameList) Populates the name set from a list of names.
private void	populate(java.lang.String nameRange) Populate the name set from an enumerated range of names.

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

getMask

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

and, andIndexFilter, not, or, orNodeFilter, toString

Methods inherited from class java.lang.Object

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

Field Detail

nameSet

private java.util.Map<java.lang.String,java.lang.Boolean> nameSet

The interned set of reference names. This is an IdentityHashMap, which compares its keys by reference for speed. This is used, since all names used in JAST are interned.

simple

private boolean simple

A flag indicating whether the reference names are simple names (true), or full identifiers (false) prefixed with a namespace identifier and colon. This affects whether matching is performed against getName() or getIdentifier().

Constructor Detail

NameSetFilter

public NameSetFilter(java.lang.String nameRange)

Creates a NameSetFilter selecting named nodes from an enumerated range. Splits the range into name tokens and adds these to the reference set. The NameSetFilter accepts all named nodes, that is, Attribute and Element nodes, whose identifier is contained in the reference set. If the search keys are all short names, matches on short names; otherwise matches on full identifiers (including the namespace prefix).

Parameters:

nameRange - an enumerated range of names.

NameSetFilter

public NameSetFilter(java.lang.String nameRange,
                     int contentType)

Creates a NameSetFilter selecting named nodes of a given content-type from an enumerated range. Splits the range into name tokens and adds these to the reference set. The NameSetFilter accepts all named nodes of the given content-type, whose identifier is contained in the reference set. If the search keys are all short names, matches on short names; otherwise matches on full identifiers (including the namespace prefix).

Parameters:

nameRange - an enumerated range of names.

contentType - a bit-mask representing one or more content-types.

NameSetFilter

private NameSetFilter(NameSetFilter filter,
                      int contentType)

Secret constructor to copy a NameSetFilter but reset the type mask. This constructor is used by the methods that logically combine this NameSetFilter with another NodeFilter. Much more efficient that having to re-analyse the set of names.

Parameters:

filter - the copied NameSetFilter.

contentType - a bit-mask specifying one or more content types.

NameSetFilter

public NameSetFilter(java.util.List<java.lang.String> nameList)

Creates a NameSetFilter selecting named nodes from a list of names. Adds the supplied names to the reference set. The NameSetFilter accepts all named nodes, that is, Attribute and Element nodes, whose identifier is contained in the reference set. If the search keys are all short names, matches on short names; otherwise matches on full identifiers (including the namespace prefix).

Parameters:

nameList - a list of reference names.

NameSetFilter

public NameSetFilter(java.util.List<java.lang.String> nameList,
                     int contentType)

Creates a NameSetFilter selecting named nodes of a given content-type from a list of names. Adds the suppled names to the reference set. The NameSetFilter accepts all named nodes of the given content-type, whose identifier is contained in the reference set. If the search keys are all short names, matches on short names; otherwise matches on full identifiers (including the namespace prefix).

Parameters:

nameList - a list of reference names.

contentType - a bit-mask representing one or more content-types.

Method Detail

populate

private void populate(java.lang.String nameRange)

Populate the name set from an enumerated range of names. Splits the name range using either a comma, a vertical bar '|', or a space, then trims leading and trailing space, then adds the interned symbols to an identity-set.

Parameters:

nameRange - an enumerated range of names to match.

populate

private void populate(java.util.List<java.lang.String> nameList)

Populates the name set from a list of names. Adds the interned names to an identity set. Sets the matching criteria to simple matching of names, unless at least one reference name is a full identifier, in which case full matching of identifiers will be performed.

Parameters:

nameList - a list of names to match.

matchName

private boolean matchName(Markup node)

Reports whether a Markup node's name is contained within the name set. Succeeds if the node's short name, or long identifier, is contained in the set. The right test to use is compiled in advance by this filter, based on the format of the reference names. If any one of these is a complex identifier, then full matching is performed against the full identifier of the node, otherwise matching is performed against the short name of the node.

Parameters:

node - the named node to match.

Returns:

true if the node's name is contained in the reference set.

accept

public boolean accept(Content node)

Reports whether a given Content node is accepted by this NameSetFilter. A node is accepted if it is a named node of the specified content-type and its short name, or long identifier, is contained in the reference set.

Overrides:

accept in class MaskFilter

Parameters:

node - a Content node.

Returns:

true, if the node is accepted, otherwise false.

andNodeFilter

protected NameSetFilter andNodeFilter(NodeFilter other)

Creates a Filter that is the conjunction of this NameSetFilter and a NodeFilter. Returns a new NameSetFilter accepting the same name, but combining the bit-masks of this and the other NodeFilter using bitwise-AND. This is more efficient than the general approach using an AndFilter.

Overrides:

andNodeFilter in class Filter

Parameters:

other - the other NodeFilter.

Returns:

a new Filter.