Top Description Fields Methods
org.apache.derby.iapi.sql.compile

public Interface ASTVisitor

extends Visitor
Imports
org.apache.derby.shared.common.error.StandardException

A Visitor which handles nodes in Derby's abstract syntax trees. In addition to this contract, it is expected that an ASTVisitor will have a 0-arg constructor. You use an ASTVisitor like this: 

// initialize your visitor
MyASTVisitor myVisitor = new MyASTVisitor();
myVisitor.initializeVisitor();
languageConnectionContext.setASTVisitor( myVisitor );

// then run your queries.
...

// when you're done inspecting query trees, release resources and
// remove your visitor
languageConnectionContext.setASTVisitor( null );
myVisitor.teardownVisitor();

Field Summary

Modifier and TypeField and Description
public static final int
AFTER_BIND

public static final int
AFTER_OPTIMIZE

public static final int
AFTER_PARSE

Method Summary

Modifier and TypeMethod and Description
public void
begin(String
Text used to create the tree.
statementText, int
of compilation (AFTER_PARSE, AFTER_BIND, or AFTER_OPTIMIZE).
phase)

The compiler calls this method just before walking a query tree.

public void
end(int
of compilation (AFTER_PARSE, AFTER_BIND, or AFTER_OPTIMIZE).
phase)

The compiler calls this method when it's done walking a tree.

public void
initializeVisitor()

Initialize the Visitor before processing any trees.

public void
teardownVisitor()

Final call to the Visitor.

Inherited from org.apache.derby.iapi.sql.compile.Visitor:
skipChildrenstopTraversalvisitvisitChildrenFirst

Field Detail

AFTER_BINDback to summary
public static final int AFTER_BIND
AFTER_OPTIMIZEback to summary
public static final int AFTER_OPTIMIZE
AFTER_PARSEback to summary
public static final int AFTER_PARSE

Method Detail

beginback to summary
public void begin(String statementText, int phase) throws StandardException

The compiler calls this method just before walking a query tree.

Parameters
statementText:String

Text used to create the tree.

phase:int

of compilation (AFTER_PARSE, AFTER_BIND, or AFTER_OPTIMIZE).

endback to summary
public void end(int phase) throws StandardException

The compiler calls this method when it's done walking a tree.

Parameters
phase:int

of compilation (AFTER_PARSE, AFTER_BIND, or AFTER_OPTIMIZE).

initializeVisitorback to summary
public void initializeVisitor() throws StandardException

Initialize the Visitor before processing any trees. User-written code calls this method before poking the Visitor into the LanguageConnectionContext. For example, an implementation of this method might open a trace file.

teardownVisitorback to summary
public void teardownVisitor() throws StandardException

Final call to the Visitor. User-written code calls this method when it is done inspecting query trees. For instance, an implementation of this method might release resources, closing files it has opened.