The Interactive Turing Machine

The Interactive Turing Machine is a web application for designing and simulating Turing machines. It was designed to be easy to use (no textual coding required) and playful (colorful graphics, animations, etc).

▶️ Open The Interactive Turing Machine simulator

📖 Read the code documentation

The project was motivated by the apparent absence of fully interactive Turing machines online (we did not cover desktop or mobile applications). As an example, most of the alternatives we found, such as turingmachinesimulator.com or turingmachine.io, required to describe the state machine using a textual language (instead of directly maniulating the graphical representation).

Interface and features

The Interactive Turing Machine simulates a Turing machine with a single semi-infinite tape to keep it simple. The interface is split in four areas:

• The main menu bar, where you can load examples, export and import machines, switch between mouse and pen & touch interaction, and open a help page (beta version only).
• The graph, where you can draw and edit the state machine using nodes (states) and edges (transitions). The generator is used as an entry point (the initial state is the state connected to the generator).
• The tape, which can be read and written (either cell-by-cell or as a string, using the edit button on the left side). The tape head indicates the current cell.
• The control panel, which displays buttons to run the machine (until it stops or until a maximum number of steps is reached), run one step only, and reset the machine (only the current state and the tape position).

If an error occurs during the simulation, a popup with a description of the error and a suggested solution will open. There currently are three types of runtime errors:

• There is no initial state.
• There is no transition available (in the current state, for the current symbol).
• There are more than one transitions available (the machine is non-deterministic, and cannot determine which transition to take).

Building process

The Interactive Turing Machine is written in TypeScript, a typed language which can be transpiled to plain JavaScript. It mainly relies on D3 for manipulating the DOM and Browserify to pack all the output JavaScript files into a single script.

To build it on your own machine, you must start by installing all the dependencies using npm. It is shipped along with Node (see installation methods).

Once this is done, open a terminal and run the following commands:

1. git clone https://github.com/Daru13/interactive-turing-machine.git to clone this repository.
2. cd interactive-turing-machine to change you working directory to the clone you just made.
3. npm install -g grunt-cli to install the CLI of Grunt, the build system we use.
4. npm install to install all the other dependencies (listed in package.json).
5. grunt to finally build the application.

The build folder will contain your own build. You can also generate your own documentation by running grunt make-doc.