title: R: regex to capture all instances after a given character
body: <p>Given string <code>ab cd  ; ef  gh ij</code>, how do I remove all spaces after the first space after <code>;</code>, i.e. <code>ab cd  ; efghij</code>? I tried using <code>\K</code> but can't get it to work completely.</p>
  
  <pre><code>test = 'ab cd  ; ef  gh ij'
  gsub('(?&lt;=; )[^ ]+\\K +','',test,perl=T)
  # "ab cd  ; efgh ij"
  </code></pre>