com.google.template.soy.basetree

Class CopyState

java.lang.Object

com.google.template.soy.basetree.CopyState

public final class CopyState
extends Object

An object that can hold extra state for tree copying operations, passed to Node.copy(CopyState).

The Soy AST is mostly a tree, but there are some back edges. Since the copying process is recursive and can be started from any node, there is no guarantee whether the back edges will be copied (this means that copying only a subtree may leave you with back edges pointing at the old tree, which is weird).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	CopyState.Listener<T> A simple listener api that can be used to listen to changes to objects via the updateRefs(T, T) api.

Constructor Summary

Constructors

Constructor and Description
CopyState()

Method Summary

Modifier and Type	Method and Description
<T> void	registerRefListener(T oldObject, CopyState.Listener<T> listener) Registers a listener to be invoked if the given object is ever updated via the updateRefs(T, T) method.
<T> void	updateRefs(T oldObject, T newObject) Registers that the old object has been remapped to the new object.

Methods inherited from class java.lang.Object

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

Constructor Detail

CopyState

public CopyState()

Method Detail

updateRefs

public <T> void updateRefs(T oldObject,
                           T newObject)

Registers that the old object has been remapped to the new object.

This is useful for auxiliary AST datastructures which may contain back-edges in the AST. When being copied, the auxiliary data structure is registered with this method then AST nodes which have references to the old copy can register via registerRefListener(T, com.google.template.soy.basetree.CopyState.Listener<T>) so that they can get a reference to the new copy as well.

registerRefListener

public <T> void registerRefListener(T oldObject,
                                    CopyState.Listener<T> listener)

Registers a listener to be invoked if the given object is ever updated via the updateRefs(T, T) method.

Note: the listener may be executed inline or not at all.