aptacode/statenet

A small .Net Standard library used to model simple State Machines

statenet's Issues

Node Machine Unit Tests

Foreach Probability Chooser:
Determine that altering each Item's Weight results in the correct distribution over a large number of calls to GetChoice.

• All exceptions are raised as expected.
• Total Weight

DeterministicChooser
That it returns the correct Choice given to the constructor.
That it returns the correct choice when updated through the Choice property.

Foreach Node:
OnVisited Fired
OnExited Fired
Moves to an expected node for a given Chooser
GetNextNodes returns expected nodes
ToString returns expected representation
Can update Chooser function

Create a NodeGraph

Instead of having to manage the creation of Nodes manually create a 'Node Graph' which based on the number of parameters given to a Factory Method manages the instantiation and connection of nodes.

E.g
nodeGraph.Add("T1", "U1", "U2", "B1", new TernaryProbabilityChooser(1, 1, 1));
nodeGraph.Add("U1", "T1");
nodeGraph.Add("U2", "T1");
nodeGraph.Add("B1", "T1", "End1", new DeterministicChooser(BinaryChoice.Item1));

Graphically create / view NodeGraphs

*** prerequisite ***
#8 (comment)

It would be very helpful for our end users to have a WPF component which allows them to visually define the relationships between nodes.

Something as primitive as:

NodeGraph IsValid

Determines if the node graph is... well.. valid.
The current approach is very naive and needs lots of work, basically return true if there exists an EndNode which you can reach from the start node.

Improvements:

1. Is there a path for which the EndNode is impossible to reach? (e.g in point 5)
2. Do all nodes have valid destination nodes?
3. Do all nodes have valid Choosers?
4. Are any exit nodes duplicates within a Node E.G a binary node (A)->(B,B) can just be a unary node (A)->(B).
5. Do any Unary nodes loop back to themselves? (A)->(A)
6. Is the start node an EndNode?

Demo's / Examples

Some demo apps / examples which would be helpful to include:

Demo's:

• A standard FSM (Traffic lights, Vending machine, Video player ect.)
• A probabilistic state machine (ABot)
• A history based state machine (such as a quiz app the chooses the next question randomly but influenced by how many times each question has been shown prior)

Defining a network:

• Using the Network Creation Tool
• From Json
• Using attributes
• In code

Node OnVisited event

Currently you have to keep a reference to a node and subscribe to its OnVisited event in order to call node.Exit() to move to the next node

For Example:

var T1 = nodeGraph.Create("T1");
T1.OnVisited += (s) =>
{
s.Exit();
};

This must be done for each node or else it will stay on that node forever.

I propose a default 'Instant transition' behaviour which moves to the next node as soo as the node is visited.

Also I propose that a subscriber can be set through the NodeGraph

nodeGraph.Visited("T1", OnT1Visited);
nodeGraph.Visited("T2", (sender)=>{ sender.Exit(); });

XML Configuration

Save / Load a graph of nodes from an XML file

Add Octary and Nonary Nodes / Choosers

Read Me

The read me needs proof reading, and the examples need updating to reflect recent changes.
A diagram showing a visual representation of the state machines would also be helpful.

Creation Tool overlapping state name bug

When changing the name of a state, if it overlaps with an existing name the new state is lost. For example, with states: Read, followed by the addition of Ready.

You can see this in action at the 10 second mark here:
https://vimeo.com/402311839
Password: "statenet"

Add methods to define all Links using references to Nodes as well as the Nodes Name

Currently we define a link like so:
nodeGraph.DeterministicLink("U1", "U2");

this can get a bit clunky in production when the node names are generated on the fly:
nodeGraph.DeterministicLink(myObject.State.ToString(), myObject.State2.ToString());

We should make overloads to the 'Link' methods in the NodeGraph which take Node References so we can do this:

var U1 = nodeGraph.Create(myObject.State.ToString());
var U2 = nodeGraph.Create(myObject.State2.ToString());
nodeGraph.DeterministicLink(U1, U2);

Optionally add a mechanisim where we can mix and match between using a Node reference and the Name
nodeGraph.DeterministicLink(U1, U2, "NewNode");

Exception Handling

There are places which return an instance of 'Exception' which lacks any detail.

Node:
All calls to Node.GetNext() should raise an exception if Destination Nodes / Chooser were not set through Visits(...)

Visits(...) should raise an Exception if the nodes / Choosers given are Null

ProbabilityChooser
should raise an exception if all ItemWeights are set to 0

NodeEngine:
Start Method should raise an exception if the graphi is not valid

Comments

Comments are lacking, Especially in the NodeMachine.