From: James Edward Gray II <james@...>
Date: 2005-08-18T12:33:42+09:00
Subject: Re: is there a shorter way to compare these 2 objects?


On Aug 17, 2005, at 10:16 PM, Lowell Kirsh wrote:

> I have a class called foo and I want to make it comparable so that  
> I can sort arrays of Foo. Here is the class:
>
> class Foo
>     attr_accessor :a, :b, :c, :d
>     def <=>(rhs); (see below); end
> end
>
> I'm assuming that the a,b,c, and d field are each Comparable. To  
> compare 2 Foos, we first look at the a's and if they're not the  
> same, we return the result of their comparison. If they are the  
> same, we continue to compare the b's, and if they're the same we  
> compare the c's, and so on until we compare the last field. So for  
> my definition of <=> I have the following, which works, but I'd  
> like something better/shorter:

def <=>( other )
   [@a, @b, @c, @d] <=> [other.a, other.b, other.c, other.d]
end

Arrays are Comparable and they compare each of their contents in order.

Hope that helps.

James Edward Gray II