bridge.reps.entities

Interface EntityFactory

All Known Implementing Classes:

EntityFactoryAdapter, EntityFactoryDefault, EntityFactoryWithMemory, EntityFactoryWithStaticMemory

public interface EntityFactory

EntityFactory Interface EntityFactory provides a module programmer with a great deal of control over how Things, Derivatives, Relations, and Sequences get created during the execution of an algorithm. For example, the Thing.deepCopy method creates many new Things as part of its operation; by providing deepCopy with a EntityFactory, you can control how the new created Things get instantiated and configured. Why would you want to use a EntityFactory? One common use in Bridge is to control how Things get stored in Memory objects. The EntityFactoryWithMemory, for example, will make sure that every Thing that is created also gets stored in a particular memory so it can be recalled later. This interface has one method corresponding to each constructor in Thing/Derivative/Relation/Sequence. To use this interface, simply replace Thing constructor calls with the appropriate EntityFactory function call. For example, the following function:

   public Thing makeATable() {
     return new Thing("table");
   }
 

would become

   public Thing makeATable(EntityFactory factory) {
     return factory.newThing("table");
   }
 

Finally, note that many of the current implementations of EntityFactory allow you to chain them together. For example, if you wanted to make sure that every Thing created is stored in both a module-specific memory and in the global default memory, you could use the following code:

   BasicMemory moduleSpecificMemory = new BasicMemory();
   EntityFactory storeInModuleFactory = new EntityFactoryWithMemory(moduleSpecificMemory);
   EntityFactory storeInBothFactory = new EntityFactoryWithStaticMemory(storeInModuleFactory);
   
   Thing myTable = makeATable(storeInBothFactory);
 

If you use chained factories, remember that each Factory in the chain acts as a filter. This means the innermost factory in the chain gets the Thing exactly as its constructor creates it, optionally modifies it a bit, and passes it to the next outer factory. Thus if you want to store only fully configure Things in memory, the Memory stages of the Factory Chain should be the outermost stages.

Author:

Keith Bonawitz

See Also:

EntityFactoryDefault, EntityFactoryWithMemory, and EntityFactoryWithStaticMemory for useful implementations of the EntityFactory interface., for a useful starting point if you want to create your own ThingFactories.

Method Summary

Methods

Modifier and Type	Method and Description
Function	newDerivative(boolean readOnly, java.lang.String suffix, Entity subject) Constructs object with a name determined by suffix string provided; used only in reading.
Function	newDerivative(Entity t)
Function	newDerivative(java.lang.String string, Entity t)
Relation	newRelation(boolean readOnly, java.lang.String suffix, Entity subject, Entity object) Constructs object with a name determined by suffix string provided; used only in reading.
Relation	newRelation(Entity subject, Entity object) Constructs a new relation, given a subject and an object.
Relation	newRelation(java.lang.String type, Entity subject, Entity object) Constructs a new relation, given a type, a subject and an object.
Sequence	newSequence() Constructs element-free sequence.
Sequence	newSequence(boolean readOnly, java.lang.String suffix) Constructs object with a name determined by suffix string provided; used only in reading.
Sequence	newSequence(java.lang.String type) Constructs element-free sequence.
Entity	newThing() Constructs object with a unique name.
Entity	newThing(boolean readOnly, java.lang.String suffix) Constructs object with a name determined by suffix string provided; used only in reading.
Entity	newThing(java.lang.String type) Creates a thing, with a type added to its primed thread.

Method Detail

newThing

Entity newThing()

Constructs object with a unique name. Adds new object instance to an instance list for later retrieval. Creates thread bundle.

newThing

Entity newThing(java.lang.String type)

Creates a thing, with a type added to its primed thread.

newThing

Entity newThing(boolean readOnly,
              java.lang.String suffix)

Constructs object with a name determined by suffix string provided; used only in reading. Adds new object instance to an instance list for later retrieval. Creates thread bundle.

newDerivative

Function newDerivative(Entity t)

newDerivative

Function newDerivative(java.lang.String string,
                     Entity t)

newDerivative

Function newDerivative(boolean readOnly,
                     java.lang.String suffix,
                     Entity subject)

Constructs object with a name determined by suffix string provided; used only in reading. Adds new object instance to an instance list for later retrieval. Creates thread bundle.

newRelation

Relation newRelation(Entity subject,
                   Entity object)

Constructs a new relation, given a subject and an object.

newRelation

Relation newRelation(java.lang.String type,
                   Entity subject,
                   Entity object)

Constructs a new relation, given a type, a subject and an object.

newRelation

Relation newRelation(boolean readOnly,
                   java.lang.String suffix,
                   Entity subject,
                   Entity object)

Constructs object with a name determined by suffix string provided; used only in reading. Adds new object instance to an instance list for later retrieval. Creates thread bundle.

newSequence

Sequence newSequence()

Constructs element-free sequence.

newSequence

Sequence newSequence(java.lang.String type)

Constructs element-free sequence.

newSequence

Sequence newSequence(boolean readOnly,
                   java.lang.String suffix)

Constructs object with a name determined by suffix string provided; used only in reading. Adds new object instance to an instance list for later retrieval. Creates thread bundle.