A Turing Machine Simulator
This project is the result of my attempt to synthesize material from two classes I am currently taking at UBC, PHIL 320 - Symbolic Logic II, and CPSC 110 - Computation, Programs, and Programming.
The design of the Turing machines I simulate is based on the presentation in Computability and Logic (Fifth Edition) by Boolos, Jeffrey, and Burgess. This machine uses a binary alphabet (including "blank" as one of the two values) and a tape which is infinite in both directions. so, as I understand from my (quite limited) historical knowledge, it is more similar to Emil Post's independently developed model of a theoretical computing machine than to the machines presented in Turing's original paper.
I have constructed it along the lines of the design method taught in CPSC 110, the online component of which is available on edX under the name Systematic Program Design, taught by Gregory Kiczales. I wrote the first version of this program about a month into the term, so as I refine it, I expect to incorporate more of what I learn about the prescribed design methodology.
This program was written in Racket, a Lisp dialect based on Scheme. Specifically, the first version of this program was written in Beginning Student Language with List Abbreviations, a "language level" of Racket with a limited vocabulary, used in the Systematic Program Design course. I may switch language levels later to take advantage of more features.
Racket and DrRacket (its companion IDE) are available here. The .rkt file is meant to be opened in DrRacket.
After running the code in DrRacket, you can generate a simulation of a turing machine by calling the main function in the REPL (input area). This call will have the form
```(main (make-config Tape Machine QNum))```
where Tape contains the starting state of the tape, Machine is a list of possible machine states (q-states), and QNum is the number of the initial state (usually 1).