title: R regex - match until first letter-space-digit combination from the end
body: <p>I have the following string vector: </p>
  
  <pre><code>x = c("Breakfast Sandwich 12.6 - 18.4oz 4 - 8ct", 
        "Buffalo Wing 7.6 - 10 oz", 
        "Asstd Cafe Appetizer 8 - 20", 
        "16in Extra Lrg Pepperoni 45.5oz") 
  </code></pre>
  
  <p>I need to move the size to the beginning of the string, but I can't create a proper <code>regex</code> call for it. If more than one combination is found, move only the last one. The part that is moved will always be preceded by a letter and space.
  The desired output will be:</p>
  
  <pre><code>"4 - 8ct Breakfast Sandwich 12.6 - 18.4oz", 
  "7.6 - 10 oz Buffalo Wing", 
  "8 - 20 Asstd Cafe Appetizer", 
  "45.5oz 16in Extra Lrg Pepperoni"
  </code></pre>
  
  <p>I think, non-greedy matching until something like <code>[a-z] [0-9].*?</code> is found? Or may be use <code>split</code> instead?
  Could you, please, help me with it? Thank you in advance!</p>
  
  <p>B.t.w., if there is no one step solution for all test cases, a series of separate <code>gsub</code> will work as well. </p>