title: YAML indentation for array in hash
body: <p>I think indentation is important in YAML.</p>
  
  <p>I tested the following in <code>irb</code>:</p>
  
  <pre><code>&gt; puts({1=&gt;[1,2,3]}.to_yaml)
  --- 
  1: 
  - 1
  - 2
  - 3
   =&gt; nil 
  </code></pre>
  
  <p>I expected something like this:</p>
  
  <pre><code>&gt; puts({1=&gt;[1,2,3]}.to_yaml)
  --- 
  1: 
    - 1
    - 2
    - 3
   =&gt; nil 
  </code></pre>
  
  <p>Why isn't there indentation for the array?</p>
  
  <p>I found this at <a href="http://www.yaml.org/YAML_for_ruby.html#collections" rel="noreferrer">http://www.yaml.org/YAML_for_ruby.html#collections</a>.</p>
  
  <blockquote>
    <p>The dash in a sequence counts as indentation, so you can add a
    sequence inside of a mapping without needing spaces as indentation.</p>
  </blockquote>