From: Alpha Chen <alpha.chen@...>
Date: 2008-05-14T01:35:03+09:00
Subject: Re: The Turing Machine (#162)

On May 12, 6:54 pm, Matthew Moss <matthew.m...@gmail.com> wrote:
> Looks like a pretty nice solution, except I think (but didn't confirm)
> there is one problem:
>
> >       @head += (dir == 'R') ? 1 : -1
>
> Doing this could cause the head to wrap around, since array[-1] in
> Ruby is the last element of the array. It's likely the examples won't
> exercise this constraint, but the tape should not loop...

That could be a problem, but I cheated: @tape is actually a hash. (I
was lazy and didn't want to make a Tape class or add extra logic to
deal with going past the front of the tape.)