Square Root function

sqrt_spec.rb

# -*- coding: utf-8 -*-

Sqrt = ->(n) {
  guess = n / 2.0
  loop do
    if (guess**2 - n) < 0.0001
      return guess
    end
    guess = (guess + n/guess) / 2.0
  end
}

require 'rspec/given'
require 'given/fuzzy_shortcuts'

describe "sqrt" do
  Then { Sqrt.(100) == 10.±(0.0001) }
end