com.oracle.truffle.api.object

Class DynamicObject

java.lang.Object

com.oracle.truffle.api.object.DynamicObject

All Implemented Interfaces:

TruffleObject

public abstract class DynamicObject
extends Object
implements TruffleObject

Represents a dynamic object, members of which can be dynamically added and removed at run time. To use it, extend DynamicObject and use DynamicObjectLibrary for object accesses. When constructing a DynamicObject, it has to be initialized with an empty initial shape. Initial shapes are created using Shape.newBuilder() and should ideally be shared per TruffleLanguage instance to allow shape caches to be shared across contexts. Subclasses can provide in-object dynamic field slots using the DynamicObject.DynamicField annotation and Shape.Builder.layout.

Example:

 
 public class MyObject extends DynamicObject implements TruffleObject {
     public MyObject(Shape shape) {
         super(shape);
     }
 }

 Shape initialShape = Shape.newBuilder().layout(MyObject.class).build();

 MyObject obj = new MyObject(initialShape);
 
 

Since:

0.8 or earlier

See Also:

DynamicObject.DynamicObject(Shape), DynamicObjectLibrary, Shape, Shape.newBuilder()

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static interface	DynamicObject.DynamicField Using this annotation, subclasses can define additional dynamic fields to be used by the object layout.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	DynamicObject(Shape shape) Constructor for DynamicObject subclasses.

Method Summary

Modifier and Type	Method and Description
protected Object	clone() The DynamicObject.clone() method is not supported by DynamicObject at this point in time, so it always throws CloneNotSupportedException, even if the Cloneable interface is implemented in a subclass.
Shape	getShape() Get the object's current shape.

Methods inherited from class java.lang.Object

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

Constructor Detail

DynamicObject

protected DynamicObject(Shape shape)

Constructor for DynamicObject subclasses. Initializes the object with the provided shape. The shape must have been constructed with a layout class assignable from this class (i.e., the concrete subclass, a superclass thereof, including DynamicObject) and must not have any instance properties (but may have constant properties).

Examples:

 Shape shape = Shape.newBuilder().build();
 DynamicObject myObject = new MyObject(shape);
 

 Shape shape = Shape.newBuilder().layout(MyObject.class).build();
 DynamicObject myObject = new MyObject(shape);
 

Parameters:

shape - the initial shape of this object

Throws:

IllegalArgumentException - if called with an illegal (incompatible) shape

Since:

19.0

Method Detail

getShape

public final Shape getShape()

Get the object's current shape.

Since:

0.8 or earlier

See Also:

Shape

clone

protected Object clone()
                throws CloneNotSupportedException

The DynamicObject.clone() method is not supported by DynamicObject at this point in time, so it always throws CloneNotSupportedException, even if the Cloneable interface is implemented in a subclass. Subclasses may however override this method and create a copy of this object by constructing a new object and copying any properties over manually.

Overrides:

clone in class Object

Throws:

CloneNotSupportedException

Since:

20.2.0