polyglot.visit
Class HandoffVisitor
java.lang.Object
polyglot.visit.NodeVisitor
polyglot.visit.HandoffVisitor
- All Implemented Interfaces:
- java.lang.Cloneable, Copy
public class HandoffVisitor
- extends NodeVisitor
This visitor adds jobs for SourceFile
s in the AST to the
schedule of another extension.
Method Summary |
Node |
leave(Node old,
Node n,
NodeVisitor v)
This method is called after all of the children of n
have been visited. |
Node |
override(Node n)
Given a tree rooted at n , the visitor has the option of
overriding all traversal of the children of n . |
Methods inherited from class polyglot.visit.NodeVisitor |
begin, copy, enter, enter, finish, finish, leave, override, toString, visitEdge, visitEdgeNoOverride |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
ext
protected ExtensionInfo ext
HandoffVisitor
public HandoffVisitor(ExtensionInfo ext)
override
public Node override(Node n)
- Description copied from class:
NodeVisitor
- Given a tree rooted at
n
, the visitor has the option of
overriding all traversal of the children of n
. If no
changes were made to n
and the visitor wishes to prevent
further traversal of the tree, then it should return n
. If
changes were made to the subtree, then the visitor should return a
copy of n
with appropriate changes. Finally, if the
visitor does not wish to override traversal of the subtree rooted at
n
, then it should return null
.
This method is typically called by the method
override(parent, n)
. If a subclass overrides the
method override(parent, n)
then this method
may not be called.
- Overrides:
override
in class NodeVisitor
- Parameters:
n
- The root of the subtree to be traversed.
- Returns:
- A node if normal traversal is to stop,
null
if it
is to continue.
leave
public Node leave(Node old,
Node n,
NodeVisitor v)
- Description copied from class:
NodeVisitor
- This method is called after all of the children of
n
have been visited. In this case, these children were visited by the
visitor v
. This is the last chance for the visitor to
modify the tree rooted at n
. This method will be called
exactly the same number of times as entry
is called.
That is, for each node that is not overriden, enter
and
leave
are each called exactly once.
Note that if old == n
then the vistior should make a copy
of n
before modifying it. It should then return the
modified copy.
This method is typically called by the method
leave(parent, old, n v)
.
If a subclass overrides the method
leave(parent, old, n v)
then this method may not be called.
- Overrides:
leave
in class NodeVisitor
- Parameters:
old
- The original state of root of the current subtree.n
- The current state of the root of the current subtree.v
- The NodeVisitor
object used to visit the children.
- Returns:
- The final result of the traversal of the tree rooted at
n
.