title: Ruby: map an array of keys to values shorthand
body: <p>I just started with Ruby recently and I'm hoping there is a shorthand for using a bound method as a proc I'm missing.  I'm trying to do this essentially</p>
  
  <pre><code>SYMBOLS = {"I" =&gt; 1, "V" =&gt; 5, "X" =&gt; 10, ... }
  
  roman = "zXXIV".upcase.chars.collect { |c| SYMBOLS[c] }
  =&gt; [nil, 10, 10, 1, 5]
  </code></pre>
  
  <p>I feel like there should be an easy way in ruby to just use SYMBOLS[] as a bound method, so just</p>
  
  <pre><code>roman = str.upcase.chars.collect &amp;:SYMBOLS[]
  </code></pre>
  
  <p><strong>Solution Ruby 1.9.3</strong></p>
  
  <p>roman = SYMBOLS.values_at(*str.upcase.chars)</p>