From: Matthew Moss <matthew.moss@...>
Date: 2008-05-14T02:03:32+09:00
Subject: Re: The Turing Machine (#162)

> > 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.)

Ah, well played, sir. I concede the point. :)