org.eclipse.jdt.core.dom
Class ASTVisitor

java.lang.Object
  |
  +--org.eclipse.jdt.core.dom.ASTVisitor

public abstract class ASTVisitor

extends Object

A visitor for abstract syntax trees.

For each different concrete AST node type T there are a pair of methods:

• public boolean visit(T node) - Visits the given node to perform some arbitrary operation. If true is returned, the given node's child nodes will be visited next; however, if false is returned, the given node's child nodes will not be visited. The default implementation provided by this class does nothing and returns true. Subclasses may reimplement this method as needed.
• public void endVisit(T node) - Visits the given node to perform some arbitrary operation. When used in the conventional way, this method is called after all of the given node's children have been visited (or immediately, if visit returned false). The default implementation provided by this class does nothing. Subclasses may reimplement this method as needed.

In addition, there are a pair of methods for visiting AST nodes in the abstract, regardless of node type:

• public void preVisit(ASTNode node) - Visits the given node to perform some arbitrary operation. This method is invoked prior to the appropriate type-specific visit method. The default implementation of this method does nothing. Subclasses may reimplement this method as needed.
• public void postVisit(ASTNode node) - Visits the given node to perform some arbitrary operation. This method is invoked after the appropriate type-specific endVisit method. The default implementation of this method does nothing. Subclasses may reimplement this method as needed.

For nodes with list-valued properties, the child nodes within the list are visited in order. For nodes with multiple properties, the child nodes are visited in the order that most closely corresponds to the lexical reading order of the source program. For instance, for a type declaration node, the child ordering is: name, superclass, superinterfaces, and body declarations.

While it is possible to modify the tree in the visitor, care is required to ensure that the consequences are as expected and desirable. During the course of an ordinary visit starting at a given node, every node in the subtree is visited exactly twice, first with visit and then with endVisit. During a traversal of a stationary tree, each node is either behind (after endVisit), ahead (before visit), or in progress (between visit and the matching endVisit). Changes to the "behind" region of the tree are of no consequence to the visit in progress. Changes to the "ahead" region will be taken in stride. Changes to the "in progress" portion are the more interesting cases. With a node, the various properties are arranged in a linear list, with a cursor that separates the properties that have been visited from the ones that are still to be visited (the cursor is between the elements, rather than on an element). The cursor moves from the head to the tail of this list, advancing to the next position just before visit if called for that child. After the child subtree has been completely visited, the visit moves on the child immediately after the cursor. Removing a child while it is being visited does not alter the course of the visit. But any children added at positions after the cursor are considered in the "ahead" portion and will be visited.

Cases to watch out for:

• Moving a child node further down the list. This could result in the child subtree being visited multiple times; these visits are sequential.
• Moving a child node up into an ancestor. If the new home for the node is in the "ahead" portion, the subtree will be visited a second time; again, these visits are sequential.
• Moving a node down into a child. If the new home for the node is in the "ahead" portion, the subtree will be visited a second time; in this case, the visits will be nested. In some cases, this can lead to a stack overflow or out of memory condition.

See Also:

ASTNode.accept(org.eclipse.jdt.core.dom.ASTVisitor)

Constructor Summary

ASTVisitor()

Method Summary

void	endVisit(AnonymousClassDeclaration node)
void	endVisit(ArrayAccess node)
void	endVisit(ArrayCreation node)
void	endVisit(ArrayInitializer node)
void	endVisit(ArrayType node)
void	endVisit(AssertStatement node)
void	endVisit(Assignment node)
void	endVisit(Block node)
void	endVisit(BooleanLiteral node)
void	endVisit(BreakStatement node)
void	endVisit(CastExpression node)
void	endVisit(CatchClause node)
void	endVisit(CharacterLiteral node)
void	endVisit(ClassInstanceCreation node)
void	endVisit(CompilationUnit node)
void	endVisit(ConditionalExpression node)
void	endVisit(ConstructorInvocation node)
void	endVisit(ContinueStatement node)
void	endVisit(DoStatement node)
void	endVisit(EmptyStatement node)
void	endVisit(ExpressionStatement node)
void	endVisit(FieldAccess node)
void	endVisit(FieldDeclaration node)
void	endVisit(ForStatement node)
void	endVisit(IfStatement node)
void	endVisit(ImportDeclaration node)
void	endVisit(InfixExpression node)
void	endVisit(Initializer node)
void	endVisit(InstanceofExpression node)
void	endVisit(Javadoc node)
void	endVisit(LabeledStatement node)
void	endVisit(MethodDeclaration node)
void	endVisit(MethodInvocation node)
void	endVisit(NullLiteral node)
void	endVisit(NumberLiteral node)
void	endVisit(PackageDeclaration node)
void	endVisit(ParenthesizedExpression node)
void	endVisit(PostfixExpression node)
void	endVisit(PrefixExpression node)
void	endVisit(PrimitiveType node)
void	endVisit(QualifiedName node)
void	endVisit(ReturnStatement node)
void	endVisit(SimpleName node)
void	endVisit(SimpleType node)
void	endVisit(SingleVariableDeclaration node)
void	endVisit(StringLiteral node)
void	endVisit(SuperConstructorInvocation node)
void	endVisit(SuperFieldAccess node)
void	endVisit(SuperMethodInvocation node)
void	endVisit(SwitchCase node)
void	endVisit(SwitchStatement node)
void	endVisit(SynchronizedStatement node)
void	endVisit(ThisExpression node)
void	endVisit(ThrowStatement node)
void	endVisit(TryStatement node)
void	endVisit(TypeDeclaration node)
void	endVisit(TypeDeclarationStatement node)
void	endVisit(TypeLiteral node)
void	endVisit(VariableDeclarationExpression node)
void	endVisit(VariableDeclarationFragment node)
void	endVisit(VariableDeclarationStatement node)
void	endVisit(WhileStatement node)
void	postVisit(ASTNode node) Visits the given AST node following the type-specific visit (after endVisit).
void	preVisit(ASTNode node) Visits the given AST node prior to the type-specific visit.
boolean	visit(AnonymousClassDeclaration node)
boolean	visit(ArrayAccess node)
boolean	visit(ArrayCreation node)
boolean	visit(ArrayInitializer node)
boolean	visit(ArrayType node)
boolean	visit(AssertStatement node)
boolean	visit(Assignment node)
boolean	visit(Block node)
boolean	visit(BooleanLiteral node)
boolean	visit(BreakStatement node)
boolean	visit(CastExpression node)
boolean	visit(CatchClause node)
boolean	visit(CharacterLiteral node)
boolean	visit(ClassInstanceCreation node)
boolean	visit(CompilationUnit node)
boolean	visit(ConditionalExpression node)
boolean	visit(ConstructorInvocation node)
boolean	visit(ContinueStatement node)
boolean	visit(DoStatement node)
boolean	visit(EmptyStatement node)
boolean	visit(ExpressionStatement node)
boolean	visit(FieldAccess node)
boolean	visit(FieldDeclaration node)
boolean	visit(ForStatement node)
boolean	visit(IfStatement node)
boolean	visit(ImportDeclaration node)
boolean	visit(InfixExpression node)
boolean	visit(Initializer node)
boolean	visit(InstanceofExpression node)
boolean	visit(Javadoc node)
boolean	visit(LabeledStatement node)
boolean	visit(MethodDeclaration node)
boolean	visit(MethodInvocation node)
boolean	visit(NullLiteral node)
boolean	visit(NumberLiteral node)
boolean	visit(PackageDeclaration node)
boolean	visit(ParenthesizedExpression node)
boolean	visit(PostfixExpression node)
boolean	visit(PrefixExpression node)
boolean	visit(PrimitiveType node)
boolean	visit(QualifiedName node)
boolean	visit(ReturnStatement node)
boolean	visit(SimpleName node)
boolean	visit(SimpleType node)
boolean	visit(SingleVariableDeclaration node)
boolean	visit(StringLiteral node)
boolean	visit(SuperConstructorInvocation node)
boolean	visit(SuperFieldAccess node)
boolean	visit(SuperMethodInvocation node)
boolean	visit(SwitchCase node)
boolean	visit(SwitchStatement node)
boolean	visit(SynchronizedStatement node)
boolean	visit(ThisExpression node)
boolean	visit(ThrowStatement node)
boolean	visit(TryStatement node)
boolean	visit(TypeDeclaration node)
boolean	visit(TypeDeclarationStatement node)
boolean	visit(TypeLiteral node)
boolean	visit(VariableDeclarationExpression node)
boolean	visit(VariableDeclarationFragment node)
boolean	visit(VariableDeclarationStatement node)
boolean	visit(WhileStatement node)

Methods inherited from class java.lang.Object

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

Constructor Detail

ASTVisitor

public ASTVisitor()

Method Detail

preVisit

public void preVisit(ASTNode node)

Visits the given AST node prior to the type-specific visit. (before visit).

The default implementation does nothing. Subclasses may reimplement.

Parameters:

node - the node to visit

postVisit

public void postVisit(ASTNode node)

Visits the given AST node following the type-specific visit (after endVisit).

The default implementation does nothing. Subclasses may reimplement.

Parameters:

node - the node to visit

visit

public boolean visit(AnonymousClassDeclaration node)

visit

public boolean visit(ArrayAccess node)

visit

public boolean visit(ArrayCreation node)

visit

public boolean visit(ArrayInitializer node)

visit

public boolean visit(ArrayType node)

visit

public boolean visit(AssertStatement node)

visit

public boolean visit(Assignment node)

visit

public boolean visit(Block node)

visit

public boolean visit(BooleanLiteral node)

visit

public boolean visit(BreakStatement node)

visit

public boolean visit(CastExpression node)

visit

public boolean visit(CatchClause node)

visit

public boolean visit(CharacterLiteral node)

visit

public boolean visit(ClassInstanceCreation node)

visit

public boolean visit(CompilationUnit node)

visit

public boolean visit(ConditionalExpression node)

visit

public boolean visit(ConstructorInvocation node)

visit

public boolean visit(ContinueStatement node)

visit

public boolean visit(DoStatement node)

visit

public boolean visit(EmptyStatement node)

visit

public boolean visit(ExpressionStatement node)

visit

public boolean visit(FieldAccess node)

visit

public boolean visit(FieldDeclaration node)

visit

public boolean visit(ForStatement node)

visit

public boolean visit(IfStatement node)

visit

public boolean visit(ImportDeclaration node)

visit

public boolean visit(InfixExpression node)

visit

public boolean visit(InstanceofExpression node)

visit

public boolean visit(Initializer node)

visit

public boolean visit(Javadoc node)

visit

public boolean visit(LabeledStatement node)

visit

public boolean visit(MethodDeclaration node)

visit

public boolean visit(MethodInvocation node)

visit

public boolean visit(NullLiteral node)

visit

public boolean visit(NumberLiteral node)

visit

public boolean visit(PackageDeclaration node)

visit

public boolean visit(ParenthesizedExpression node)

visit

public boolean visit(PostfixExpression node)

visit

public boolean visit(PrefixExpression node)

visit

public boolean visit(PrimitiveType node)

visit

public boolean visit(QualifiedName node)

visit

public boolean visit(ReturnStatement node)

visit

public boolean visit(SimpleName node)

visit

public boolean visit(SimpleType node)

visit

public boolean visit(StringLiteral node)

visit

public boolean visit(SuperConstructorInvocation node)

visit

public boolean visit(SuperFieldAccess node)

visit

public boolean visit(SuperMethodInvocation node)

visit

public boolean visit(SwitchCase node)

visit

public boolean visit(SwitchStatement node)

visit

public boolean visit(SynchronizedStatement node)

visit

public boolean visit(ThisExpression node)

visit

public boolean visit(ThrowStatement node)

visit

public boolean visit(TryStatement node)

visit

public boolean visit(TypeDeclaration node)

visit

public boolean visit(TypeDeclarationStatement node)

visit

public boolean visit(TypeLiteral node)

visit

public boolean visit(SingleVariableDeclaration node)

visit

public boolean visit(VariableDeclarationExpression node)

visit

public boolean visit(VariableDeclarationStatement node)

visit

public boolean visit(VariableDeclarationFragment node)

visit

public boolean visit(WhileStatement node)

endVisit

public void endVisit(AnonymousClassDeclaration node)

endVisit

public void endVisit(ArrayAccess node)

endVisit

public void endVisit(ArrayCreation node)

endVisit

public void endVisit(ArrayInitializer node)

endVisit

public void endVisit(ArrayType node)

endVisit

public void endVisit(AssertStatement node)

endVisit

public void endVisit(Assignment node)

endVisit

public void endVisit(Block node)

endVisit

public void endVisit(BooleanLiteral node)

endVisit

public void endVisit(BreakStatement node)

endVisit

public void endVisit(CastExpression node)

endVisit

public void endVisit(CatchClause node)

endVisit

public void endVisit(CharacterLiteral node)

endVisit

public void endVisit(ClassInstanceCreation node)

endVisit

public void endVisit(CompilationUnit node)

endVisit

public void endVisit(ConditionalExpression node)

endVisit

public void endVisit(ConstructorInvocation node)

endVisit

public void endVisit(ContinueStatement node)

endVisit

public void endVisit(DoStatement node)

endVisit

public void endVisit(EmptyStatement node)

endVisit

public void endVisit(ExpressionStatement node)

endVisit

public void endVisit(FieldAccess node)

endVisit

public void endVisit(FieldDeclaration node)

endVisit

public void endVisit(ForStatement node)

endVisit

public void endVisit(IfStatement node)

endVisit

public void endVisit(ImportDeclaration node)

endVisit

public void endVisit(InfixExpression node)

endVisit

public void endVisit(InstanceofExpression node)

endVisit

public void endVisit(Initializer node)

endVisit

public void endVisit(Javadoc node)

endVisit

public void endVisit(LabeledStatement node)

endVisit

public void endVisit(MethodDeclaration node)

endVisit

public void endVisit(MethodInvocation node)

endVisit

public void endVisit(NullLiteral node)

endVisit

public void endVisit(NumberLiteral node)

endVisit

public void endVisit(PackageDeclaration node)

endVisit

public void endVisit(ParenthesizedExpression node)

endVisit

public void endVisit(PostfixExpression node)

endVisit

public void endVisit(PrefixExpression node)

endVisit

public void endVisit(PrimitiveType node)

endVisit

public void endVisit(QualifiedName node)

endVisit

public void endVisit(ReturnStatement node)

endVisit

public void endVisit(SimpleName node)

endVisit

public void endVisit(SimpleType node)

endVisit

public void endVisit(StringLiteral node)

endVisit

public void endVisit(SuperConstructorInvocation node)

endVisit

public void endVisit(SuperFieldAccess node)

endVisit

public void endVisit(SuperMethodInvocation node)

endVisit

public void endVisit(SwitchCase node)

endVisit

public void endVisit(SwitchStatement node)

endVisit

public void endVisit(SynchronizedStatement node)

endVisit

public void endVisit(ThisExpression node)

endVisit

public void endVisit(ThrowStatement node)

endVisit

public void endVisit(TryStatement node)

endVisit

public void endVisit(TypeDeclaration node)

endVisit

public void endVisit(TypeDeclarationStatement node)

endVisit

public void endVisit(TypeLiteral node)

endVisit

public void endVisit(SingleVariableDeclaration node)

endVisit

public void endVisit(VariableDeclarationExpression node)

endVisit

public void endVisit(VariableDeclarationStatement node)

endVisit

public void endVisit(VariableDeclarationFragment node)

endVisit

public void endVisit(WhileStatement node)