title: What is an eloquent way to sort an array of hashes based on whether a key is empty in Ruby?
body: <pre><code>array = [{ name:'Joe', foo:'bar' },
           { name:'Bob', foo:''    },
           { name:'Hal', foo:'baz' }
          ]
  </code></pre>
  
  <p>What is an eloquent way to sort so that if foo is empty, then put it at the end, and not change the order of the other elements?</p>
  
  <p>Ruby 1.9.3</p>