com.foundationdb.sql.parser

Interface ASTVisitor

All Superinterfaces:

Visitor

public interface ASTVisitor
extends Visitor

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

Fields

Modifier and Type	Field and Description
static int	AFTER_BIND
static int	AFTER_OPTIMIZE
static int	AFTER_PARSE

Method Summary

Methods

Modifier and Type	Method and Description
void	begin(String statementText, int phase) The compiler calls this method just before walking a query tree.
void	end(int phase) The compiler calls this method when it's done walking a tree.
void	initializeVisitor() Initialize the Visitor before processing any trees.
void	teardownVisitor() Final call to the Visitor.

Methods inherited from interface com.foundationdb.sql.parser.Visitor

skipChildren, stopTraversal, visit, visitChildrenFirst

Field Detail

AFTER_PARSE

static final int AFTER_PARSE

See Also:

Constant Field Values

AFTER_BIND

static final int AFTER_BIND

See Also:

Constant Field Values

AFTER_OPTIMIZE

static final int AFTER_OPTIMIZE

See Also:

Constant Field Values

Method Detail

initializeVisitor

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.

Throws:

StandardException

teardownVisitor

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.

Throws:

StandardException

begin

void begin(String statementText,
         int phase)
           throws StandardException

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

Parameters:

statementText - Text used to create the tree.

phase - of compilation (AFTER_PARSE, AFTER_BIND, or AFTER_OPTIMIZE).

Throws:

StandardException

end

void end(int phase)
         throws StandardException

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

Parameters:

phase - of compilation (AFTER_PARSE, AFTER_BIND, or AFTER_OPTIMIZE).

Throws:

StandardException