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 final int
     
    static final int
     
    static final int
     
  • Method Summary

    Modifier and Type
    Method
    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
    Initialize the Visitor before processing any trees.
    void
    Final call to the Visitor.

    Methods inherited from interface org.apache.derby.iapi.sql.compile.Visitor

    skipChildren, stopTraversal, visit, visitChildrenFirst
  • Field Details

  • Method Details

    • 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