RCR 62: Kernel::rand to accept Range

  (45..96).rand<br>

  [23, 67, 34, 68].rand<br>

  def rand() at super(size)<br>
  end<br>

then to put a random item from a range:

<tt> (0..10).to_a.rand </tt>

to get a random line from a file:

<tt> File.new("foo.txt", "r").read.split.rand </tt>

I'm not convinced that it makes sense to make this an instance method. Here's an implentation that overrides rand() to work on any container that has size() and each() defined:

module Kernel

  orig_rand = method(:rand)
  define_method(:rand) do |x|
    if x.respond_to?(:each) and x.respond_to?(:size) then
      raise ArgumentError, "Invalid container size" if x.size == 0
      n = rand(x.size); j = 0
      for y in x do
        break if j == n
        j += 1
      end
      y # return
    else
      orig_rand.call(x) # return
    end
  end

end
p rand(10)
p rand(2..20)
p rand([100, 200, 300, 400])
p rand({1=>2, 2=>3, 3=>4, 4=>5})

Kernel#rand(min = 0, max = 1, int = false)

Seems excessive to need a range object to specify a lower and upper bound. It'd be nice to specify whether or not it should be an int too. ;~) More sugar. :~)