title: Extract longest word in string
body: <p>I would like to find and extract the longest word of a string, if possible using a <code>tidyverse</code> package. </p>
  
  <pre><code>library(tidyverse)
  
  tbl &lt;- tibble(a=c("ab cde", "bcde f", "cde fg"), b=c("cde", "bcde", "cde"))
  tbl
  # A tibble: 3 x 1
     a
  &lt;chr&gt;
  1 ab cde
  2 bcde f
  3 cde fg
  </code></pre>
  
  <p>The result I am looking for is:</p>
  
  <pre><code># A tibble: 3 x 2
     a     b
    &lt;chr&gt; &lt;chr&gt;
  1 ab cde   cde
  2 bcde f  bcde
  3 cde fg   cde
  </code></pre>
  
  <p>The closest post to the question I have found is this: <a href="https://stackoverflow.com/questions/4599174/longest-word-in-a-string">longest word in a string</a>. Does anyone have an idea for an even simpler way?</p>