From: markus heiler <shevegen@...>
Date: 2011-11-07T08:25:22+09:00
Subject: [ruby-core:40802] [ruby-trunk - Feature #5574] Make arrays comparable


Issue #5574 has been updated by markus heiler.


Ok so it does not yet exist because it can contain elements that are not comparable.

But in the example given with the 1, 2] < [1, 1] all elements are comparable. Ruby wants you to include Comparable.

But even when you do that, and then try to compare an invalid Array element:

[1, 2] < [1, "adc"]

You get an argument error:
        
  ArgumentError: comparison of Array with Array failed

So I think the better way would be to include Comparable module in Array?
----------------------------------------
Feature #5574: Make arrays comparable
http://redmine.ruby-lang.org/issues/5574

Author: Arnau Sanchez
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 


Why are arrays not comparable? _Array_ already defines _<=>_, so it seems only natural to mix-in the _Comparable_ module.

<pre>
> [1, 2] < [1, 1] 
NoMethodError: undefined method `<' for [1, 2]:Array

> Array.send(:include, Comparable)
> [1, 2] < [1, 1] 
=> false
</pre>

This was already discussed in the mailing list a while ago and people agreed it would be useful:

http://www.ruby-forum.com/topic/76535


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