ReteCore.IndexedExistsNode Class Reference

The IndexedExistsNode class represents a node in a Rete network that efficiently implements the "exists" condition by maintaining indexed collections of tokens and facts. The left side of the node (tokens) is indexed by a key extracted from the tokens, while the right side (facts) is indexed by a key extracted from the facts. More...

Inheritance diagram for ReteCore.IndexedExistsNode:

Public Member Functions
	IndexedExistsNode (string name, Func< Token, object > leftKey, Func< object, object > rightKey)
	The constructor for the IndexedExistsNode takes a name for identification, and two selector functions that extract the join key from tokens and facts.
void	AddSuccessor (IReteNode node)
	Adds a successor node to this IndexedExistsNode. Successors will receive propagated assertions and retractions when matches are found or lost.
void	Assert (object factOrToken)
	The Assert method takes either a Token (from the left side) or a fact (from the right side) and updates the internal indexes accordingly. It then propagates assertions to successors if matches are found.
void	AssertLeft (Token token)
	Asserts a token on the left side of the node. It updates the left index and checks for matches on the right side using the extracted key. If matches are found, it propagates assertions to successors.
void	AssertRight (object fact)
	Asserts a fact on the right side of the node. It updates the right index and checks for matches on the left side using the extracted key. If matches are found, it propagates assertions to successors.
void	Retract (object factOrToken)
	The Retract method takes either a Token (from the left side) or a fact (from the right side) and updates the internal indexes accordingly. It then propagates retractions to successors if matches are lost.
void	RetractLeft (Token token)
	Retracts a token from the left side of the node. It updates the left index and checks for matches on the right side using the extracted key. If matches are lost, it propagates retractions to successors.
void	RetractRight (object fact)
	Retracts a fact from the right side of the node. It updates the right index and checks for matches on the left side using the extracted key. If matches are lost, it propagates retractions to successors.
void	Refresh (object fact, string propertyName)
	The Refresh method is used to update the state of a fact or token in the node without changing its presence. For simplicity, we will treat Refresh as a Retract followed by an Assert, which will trigger the necessary updates to successor nodes based on the current state of matches.
void	DebugPrint (object fact, int level=0)
	Prints the internal state of the node for debugging purposes. It shows the current tokens and facts in the indexes, as well as the matches for each token. This can be useful for understanding how the node is processing assertions and retractions.

Detailed Description

The IndexedExistsNode class represents a node in a Rete network that efficiently implements the "exists" condition by maintaining indexed collections of tokens and facts. The left side of the node (tokens) is indexed by a key extracted from the tokens, while the right side (facts) is indexed by a key extracted from the facts.

Constructor & Destructor Documentation

IndexedExistsNode()

ReteCore.IndexedExistsNode.IndexedExistsNode	(	string	name,
		Func< Token, object >	leftKey,
		Func< object, object >	rightKey )

The constructor for the IndexedExistsNode takes a name for identification, and two selector functions that extract the join key from tokens and facts.

Parameters

name	The name of this node as identification.
leftKey	The left token selector function.
rightKey	The right fact selector function.

Member Function Documentation

AddSuccessor()

void ReteCore.IndexedExistsNode.AddSuccessor

(

IReteNode

node

)

Adds a successor node to this IndexedExistsNode. Successors will receive propagated assertions and retractions when matches are found or lost.

Parameters

node	The node to add this node to as a successor.

Assert()

void ReteCore.IndexedExistsNode.Assert

(

object

factOrToken

)

The Assert method takes either a Token (from the left side) or a fact (from the right side) and updates the internal indexes accordingly. It then propagates assertions to successors if matches are found.

Parameters

factOrToken

The fact or token this operation is acting upon.

Implements ReteCore.IReteNode.

AssertLeft()

void ReteCore.IndexedExistsNode.AssertLeft

(

Token

token

)

Asserts a token on the left side of the node. It updates the left index and checks for matches on the right side using the extracted key. If matches are found, it propagates assertions to successors.

Parameters

token

The token this operation is acting upon.

AssertRight()

void ReteCore.IndexedExistsNode.AssertRight

(

object

fact

)

Asserts a fact on the right side of the node. It updates the right index and checks for matches on the left side using the extracted key. If matches are found, it propagates assertions to successors.

Parameters

fact	The fact this operation is acting upon.

DebugPrint()

void ReteCore.IndexedExistsNode.DebugPrint	(	object	fact,
		int	level = 0 )

Prints the internal state of the node for debugging purposes. It shows the current tokens and facts in the indexes, as well as the matches for each token. This can be useful for understanding how the node is processing assertions and retractions.

Parameters

fact	The fact whose information is to be output.
level	A level of indentation.

Implements ReteCore.IReteNode.

Refresh()

void ReteCore.IndexedExistsNode.Refresh	(	object	fact,
		string	propertyName )

The Refresh method is used to update the state of a fact or token in the node without changing its presence. For simplicity, we will treat Refresh as a Retract followed by an Assert, which will trigger the necessary updates to successor nodes based on the current state of matches.

Parameters

factOrToken	The fact or token this operation is acting upon.
propertyName	The name of the property in the fact cell that is being updated.

Implements ReteCore.IReteNode.

Retract()

void ReteCore.IndexedExistsNode.Retract

(

object

factOrToken

)

The Retract method takes either a Token (from the left side) or a fact (from the right side) and updates the internal indexes accordingly. It then propagates retractions to successors if matches are lost.

Parameters

factOrToken

The fact or token this operation is acting upon.

Implements ReteCore.IReteNode.

RetractLeft()

void ReteCore.IndexedExistsNode.RetractLeft

(

Token

token

)

Retracts a token from the left side of the node. It updates the left index and checks for matches on the right side using the extracted key. If matches are lost, it propagates retractions to successors.

Parameters

token

The token this operation is acting upon.

RetractRight()

void ReteCore.IndexedExistsNode.RetractRight

(

object

fact

)

Retracts a fact from the right side of the node. It updates the right index and checks for matches on the left side using the extracted key. If matches are lost, it propagates retractions to successors.

Parameters

fact	The fact this operation is acting upon.

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The documentation for this class was generated from the following file:

• ReteCore/IndexedExistsNode.cs