com.metamatrix.query.sql.visitor
Class ElementCollectorVisitor

java.lang.Object
  com.metamatrix.query.sql.LanguageVisitor
      com.metamatrix.query.sql.visitor.ElementCollectorVisitor

public class ElementCollectorVisitor
extends LanguageVisitor

This visitor class will traverse a language object tree and collect all element symbol references it finds. It uses a collection to collect the elements in so different collections will give you different collection properties - for instance, using a Set will remove duplicates.

The easiest way to use this visitor is to call the static methods which create the visitor (and possibly the collection), run the visitor, and return the collection. The public visit() methods should NOT be called directly.

Constructor Summary

ElementCollectorVisitor(java.util.Collection elements)
Construct a new visitor with the specified collection, which should be non-null.

Method Summary

java.util.Collection	getElements() Get the elements collected by the visitor.
static void	getElements(java.util.Collection<LanguageObject> objs, java.util.Collection elements)
static java.util.Collection<ElementSymbol>	getElements(LanguageObject obj, boolean removeDuplicates) Helper to quickly get the elements from obj in a collection.
static java.util.Collection	getElements(LanguageObject obj, boolean removeDuplicates, boolean useDeepIteration) Helper to quickly get the elements from obj in a collection.
static void	getElements(LanguageObject obj, java.util.Collection elements) Helper to quickly get the elements from obj in the elements collection
void	visit(AllInGroupSymbol obj) Visit a language object and collect symbols.
void	visit(AllSymbol obj) Visit a language object and collect symbols.
void	visit(ElementSymbol obj) Visit a language object and collect symbols.

Methods inherited from class com.metamatrix.query.sql.LanguageVisitor

setAbort, shouldAbort, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit

Methods inherited from class java.lang.Object

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

Constructor Detail

ElementCollectorVisitor

public ElementCollectorVisitor(java.util.Collection elements)

Construct a new visitor with the specified collection, which should be non-null.

Parameters:

elements - Collection to use for elements

Throws:

java.lang.IllegalArgumentException - If elements is null

Method Detail

getElements

public java.util.Collection getElements()

Get the elements collected by the visitor. This should best be called after the visitor has been run on the language object tree.

Returns:

Collection of ElementSymbol

visit

public void visit(ElementSymbol obj)

Visit a language object and collect symbols. This method should NOT be called directly.

Overrides:

visit in class LanguageVisitor

Parameters:

obj - Language object

visit

public void visit(AllInGroupSymbol obj)

Visit a language object and collect symbols. This method should NOT be called directly.

Overrides:

visit in class LanguageVisitor

Parameters:

obj - Language object

visit

public void visit(AllSymbol obj)

Visit a language object and collect symbols. This method should NOT be called directly.

Overrides:

visit in class LanguageVisitor

Parameters:

obj - Language object

getElements

public static final void getElements(LanguageObject obj,
                                     java.util.Collection elements)

Helper to quickly get the elements from obj in the elements collection

Parameters:

obj - Language object

elements - Collection to collect elements in

getElements

public static final void getElements(java.util.Collection<LanguageObject> objs,
                                     java.util.Collection elements)

getElements

public static final java.util.Collection<ElementSymbol> getElements(LanguageObject obj,
                                                                    boolean removeDuplicates)

Helper to quickly get the elements from obj in a collection. The removeDuplicates flag affects whether duplicate elements will be filtered out.

Parameters:

obj - Language object

removeDuplicates - True to remove duplicates

Returns:

Collection of ElementSymbol

getElements

public static final java.util.Collection getElements(LanguageObject obj,
                                                     boolean removeDuplicates,
                                                     boolean useDeepIteration)

Helper to quickly get the elements from obj in a collection. The removeDuplicates flag affects whether duplicate elements will be filtered out.

Parameters:

obj - Language object

removeDuplicates - True to remove duplicates

useDeepIteration - indicates whether or not to iterate into nested subqueries of the query

Returns:

Collection of ElementSymbol