From: James Edward Gray II <james@...>
Date: 2006-08-16T07:04:33+09:00
Subject: Re: [QUIZ] Newbie doubts about the quiz

On Aug 15, 2006, at 3:49 PM, Marcelo Alvim wrote:

> 1) I could create a class that extends Array, or encapsulates one, and
> define the #[] and #[]= methods. Then those methods would check the
> negative indices and return nil if they were negative.

I think this solution would work out fine.  Others have given you  
great ideas as well.

Here's a validation method used in David Tran's solution to verify  
that the indices selected are good:

    def valid(x, y)
      x >= 0 && x < @size && y >= 0 && y < @size && !@board[x][y]
    end

See how it ensures they are between 0 and @size?  It also checks that  
the @board is nil at x, y.

Hope that helps.

James Edward Gray II