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 Description static int
AFTER_BIND
static int
AFTER_OPTIMIZE
static int
AFTER_PARSE
-
Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description void
begin(java.lang.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 org.apache.derby.iapi.sql.compile.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(java.lang.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
-
-