title: What is the "equals greater than" operator => in Ruby?
body: <p>In a Ruby on Rails tutorial, I am asked to type:</p>
  
  <pre><code>class Post &lt; ActiveRecord::Base
      validates :name,  :presence =&gt; true  
      validates :title, :presence =&gt; true, :length =&gt; { :minimum =&gt; 5 }
  end
  </code></pre>
  
  <p>I understand what this does, but I would like to know what the => operator is. In PHP-land, it links a key and a value in an associative array. Is it the same thing here? Is it a Ruby operator or a Rails operator?</p>