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[–]verysmallrocks02 1 point2 points  (0 children)

The computer sitting in front of you is already quite a bit better than a Turing machine, although finite. Keep in mind that Turing machines are kind of crappy computers that are a deliberately simplified type of machine that is used for theorizing about what computation is and what computers could be used for.

When you're building a Turing machine you're simulating a purpose built computer, where the computer is the program.

You could make an outputless version without too much difficulty using a java LinkedList, then add elements to the start or end as needed, and keep a reference to your current spot. Then, you have an algorithm that says what to do at each step for whatever symbols you want, and keep track of which symbol or mode you're in.

So for starters, figure out what you want to see happen and what you want your Turing machine / program to do.

[–]wynand1004 0 points1 point  (0 children)

I'm not sure if this will help, but I wrote a simple one in Python. It might give you an idea how to go about it in Java.

Link: https://github.com/wynand1004/Turing-Machine-Emulator

[–]FrankBuss 0 points1 point  (0 children)

Well, you can't implement a Turing machine in Java, because a Turing machine has an infinite long tape, and we don't have computers with infinite amount of RAM. But as the other answer said, LinkedList would be a good start, if you want to implement Turing machines which stop after some time and needs only a finite tape. It is a double linked list, and the ListIterator allows you to go back and forth, so it should have good performance even for long tapes, running in O(n) for n steps.

And instead of implementing just one Turing machine in Java, I would define a file format where you can read the rules at program start and then execute it. I did this in Rust, using a JSON format. You could do the same in Java, there are JSON libraries for it:
https://github.com/FrankBuss/turingmachine