From: Caleb Tennis <caleb@...>
Date: 2005-11-26T02:57:01+09:00
Subject: Re: Newbie Mixin Problem

On Friday 25 November 2005 12:47 pm, jlr8 wrote:

> Each Player has two Strategies and Boards represent these. When
> creating a Board instance I can use validIndex?, however when creating
> a Strategy or Player (which creates new Boards) I get:
>
> NoMethodError: undefined method `validIndex?' for Board:Class

It looks to me like you're calling validIndex? on Board, and not on an 
instance of a Board.  Consider this code:

irb(main):001:0> Object.foo
NoMethodError: undefined method `foo' for Object:Class
        from (irb):1

irb(main):002:0> a = Object.new
=> #<Object:0xb7ca26c8>
irb(main):003:0> a.foo
NoMethodError: undefined method `foo' for #<Object:0xb7ca26c8>

See the difference in the errors?

Also, you can simplify your code a little bit:

def validIndex?(index)
  return index.between?(0, MAX_ENTRIES)
end