org.imemex.logicalplan.treewalkers
Class AbstractTreeWalker

java.lang.Object
  org.imemex.logicalplan.treewalkers.AbstractTreeWalker

All Implemented Interfaces:

LogicalTreeWalker

Direct Known Subclasses:

AbstractRewriteRule, CanonicalOrder, ContextTransformer, DataSourcePluginAnalyzer, DefaultSemanticITrailHandler, iTrailDictionaryBox, LogicalNodeIdentifier, LogNodeSimplePrinter, LogNodeXMLPrinter, LogTreeAnnotate, SnapshotSemanticITrailMatcher, TestTreeWalker, WarehouseAnalyzer

public abstract class AbstractTreeWalker
extends java.lang.Object
implements LogicalTreeWalker

Version:

1.0

Author:

ogirard

Constructor Summary

AbstractTreeWalker(LogicalNode pattern)
instantiate tree walker for pattern

AbstractTreeWalker(java.lang.String patternString)
instantiate tree walker for pattern string

AbstractTreeWalker(java.lang.String[] patternStrings)
instantiate tree walker for pattern strings

Method Summary

static <T extends AbstractTreeWalker> LogicalNode	applyRules(java.util.List<T> rules, LogicalNode node) Try to rewrite given logical node using the given rules.
boolean	defaultMatch(LogicalNode node) call this method if you want to use the default pattern matching one of the indicated pattern has to hold only (OR).
LogicalNode	doAfterEnd(LogicalNode node) This method is executed after the tree has been traversed
LogicalNode	doBeforeStart(LogicalNode node) This method is executed before the tree is traversed.
java.util.Iterator<LogicalNode>	getMatches(LogicalNode lognode) gets iterator of all matching nodes
LogicalNode[]	getPatterns() gets pattern
boolean	hasMatch(LogicalNode node) traverses tree recursively and checks if match present
LogicalNode	processTree(LogicalNode lognode) processes logical tree and rewrites matching nodes NO recursive application of action.
LogicalNode	processTree(LogicalNode lognode, boolean rec) processes logical tree and rewrites matching nodes
boolean	wasChanged()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractTreeWalker

public AbstractTreeWalker(LogicalNode pattern)

instantiate tree walker for pattern

Parameters:

pattern -

AbstractTreeWalker

public AbstractTreeWalker(java.lang.String patternString)

instantiate tree walker for pattern string

Parameters:

patternString -

See Also:

LogicalPattern

AbstractTreeWalker

public AbstractTreeWalker(java.lang.String[] patternStrings)

instantiate tree walker for pattern strings

Parameters:

pattern -

See Also:

LogicalPattern

Method Detail

defaultMatch

public boolean defaultMatch(LogicalNode node)

call this method if you want to use the default pattern matching
one of the indicated pattern has to hold only (OR).

Parameters:

node - input node

Returns:

true if node matches pattern, false otherwise

doBeforeStart

public LogicalNode doBeforeStart(LogicalNode node)

Description copied from interface: LogicalTreeWalker

This method is executed before the tree is traversed.

Specified by:

doBeforeStart in interface LogicalTreeWalker

Parameters:

node - tree root before execution

Returns:

doAfterEnd

public LogicalNode doAfterEnd(LogicalNode node)

Description copied from interface: LogicalTreeWalker

This method is executed after the tree has been traversed

Specified by:

doAfterEnd in interface LogicalTreeWalker

Parameters:

node - tree root after execution

Returns:

hasMatch

public boolean hasMatch(LogicalNode node)

Description copied from interface: LogicalTreeWalker

traverses tree recursively and checks if match present

Specified by:

hasMatch in interface LogicalTreeWalker

processTree

public LogicalNode processTree(LogicalNode lognode,
                               boolean rec)

Description copied from interface: LogicalTreeWalker

processes logical tree and rewrites matching nodes

Specified by:

processTree in interface LogicalTreeWalker

Parameters:

lognode - logical tree to be processed

rec - true if recursion is enabled (meaning: inserted parts may be replaced again)
false if only matches in the original tree should be considered

Returns:

rewritten tree

processTree

public LogicalNode processTree(LogicalNode lognode)

Description copied from interface: LogicalTreeWalker

processes logical tree and rewrites matching nodes
NO recursive application of action.

Specified by:

processTree in interface LogicalTreeWalker

Parameters:

lognode - logical tree to be processed

Returns:

rewritten tree

getPatterns

public LogicalNode[] getPatterns()

Description copied from interface: LogicalTreeWalker

gets pattern

Specified by:

getPatterns in interface LogicalTreeWalker

Returns:

getMatches

public java.util.Iterator<LogicalNode> getMatches(LogicalNode lognode)

Description copied from interface: LogicalTreeWalker

gets iterator of all matching nodes

Specified by:

getMatches in interface LogicalTreeWalker

Returns:

wasChanged

public boolean wasChanged()

applyRules

public static <T extends AbstractTreeWalker> LogicalNode applyRules(java.util.List<T> rules,
                                                                    LogicalNode node)

Try to rewrite given logical node using the given rules. If node could be rewritten, a rewritten copy will be returned, otherwise the original node is returned.

Parameters:

rules - rules to try.

node - logical node who should be rewritten.