Re: Why is Array not Comparable

David A. Black wrote:
> Array#sort depends on the array's elements responding to <=>...
Just like Array#<=> :) That was my point.

We already have methods that depend on all elements being <=> to each
other (#<=>, #sort, #sort!).

* If this is okay, there's no reason against Comparable Array.
* If this is evil, #sort has to go. Which would be madness.

IMO, it won't hurt. But it can be useful, even sweet:

  class Array
    include Comparable
  end

  # Binary arithmetic (bit vector element-wise comparison)
  class Integer
    def bits
      to_s(2).chars.map(&:to_i)
    end
  end

  1995.bits  # => [1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1]
  1995.bits < 2008.bits  # => true

  # Decimal-safe version check
  RUBY_VERSION  # => "1.9.0"
  RUBY_VERSION >= '1.9'  # => true
  RUBY_VERSION >= '1.10'  # => true
  RUBY_VERSION.split('.').map(&:to_i) >= [1, 9]  # => true
  RUBY_VERSION.split('.').map(&:to_i) >= [1, 10]  # => false

Rick DeNatale wrote:
> ...you-cant-judge-a-book-some-mental-traps-in-learning-ruby
(pretty *long* URLs!)
Yes...you can't judge a book by its cover. Which is great for books and
people, but not necessarily for a programming language. I think it is
one of the implications of duck typing, and I would make that trade.

Remember you can shoot your feet in any language:

  [1].cycle.sort  # start CPU fan

[murphy]