Automata documentation

Welcome to the documentation for Automata.

---

API Documentation

• Automata.Core
  • Automata.Core.Alang
  • Automata.Core.Operations
• Automata.Visualization

---

Automata source code repo at GitHub

---

ALANG - A language for definining finite-state automata.

Alang is a formal language for defining finite-state automata using human-readable regular expressions. It supports many operations, such as union, intersection, complement and set difference, enabling expressions like (a? (b | c)* - (b b))+.

Alang documentation

---

Automaton types

The automaton types in the Automata library are:

C# class	Automaton type	Mutable	Internal Representation	Transition/state access	Memory Footprint
Nfa	Non-deterministic FSA	Yes	Dual Red-Black Trees	O(log n)	Medium
Dfa	Deterministic FSA	Yes	Red-Black Tree	O(log n)	Low
Mfa	Minimal Canonical FSA	No	Contiguous memory block	O(log n)	Very low

---

C# Examples: Create and Operate on Automata

The following examples creates FSAs from regular expressions in Alang.

📄 Example: Console application using Automata.Core

using Automata.Core;
using Automata.Core.Alang;
using Automata.Core.Operations;

namespace Automata.App;

public static class Program
{
    public static void Main()
    {
        // Compile a regex to a FSA (all sequences of {a, b, c} where any 'a' must be followed by 'b' or 'c')
        var fsa = AlangRegex.Compile("(a? (b | c) )+");

        // Compile two other automata
        var test1 = AlangRegex.Compile("a b b c b");
        var test2 = AlangRegex.Compile("a b a a b");

        // Test the language overlap of the FSA with the two test regexes
        Console.WriteLine(fsa.Overlaps(test1)); //output: true
        Console.WriteLine(fsa.Overlaps(test2)); //output: false
    }
}

---

📄 Example: Console application using Automata.Visualization

The application will display the following automaton in a new window:

using Automata.Core;
using Automata.Core.Alang;
using Automata.Core.Operations;
using Automata.Visualization;

namespace Automata.App;
public static class Program
{
    public static void Main()
    {
        var fsa = AlangRegex.Compile("(a? (b | c) )+");  // Create an FSA from a regex

        Console.WriteLine("Creating a minimal FSA and displaying it."); // Write some info to the console

        var graph = fsa.CreateGraph(displayStateIDs: true); // Create a graph object (FSA with layout) 

        GraphView graphView = GraphView.OpenNew(graph); // Open a new non-modal window that displays the graph

        Console.WriteLine("FSA is displayed."); // Write some info to the console
    }
}

---