title: Other Ruby Map Shorthand Notation
body: <p>I am aware of the shorthand for map that looks like:</p>
  
  <pre><code>[1, 2, 3, 4].map(&amp;:to_s)
  &gt; ["1", "2", "3", "4"]
  </code></pre>
  
  <p>I was told this is shorthand for:</p>
  
  <pre><code>[1, 2, 3, 4].map{|i| i.to_s}
  </code></pre>
  
  <p>This makes perfect sense. My question is this: It seems there should be an easier way to write:</p>
  
  <pre><code>[1, 2, 3, 4].map{|x| f.call(x)} 
  </code></pre>
  
  <p>for some procedure f. I know the way I just typed isn't all that long to begin with, but I'd contend that neither is the previous example for which the shorthand exists. This example just seems like the complement to the first example: Rather than calling i's to_s method for every i, I wish to call f for every x. </p>
  
  <p>Does such a shorthand exist?</p>