title: Xcode lagging in large swift files
body: <p>Why does Xcode lag in large files and does anyone know how to stop this?</p>
  
  <p>I have a .swift file which is 8,000+ lines of code and when I try to modify the file Xcode changes my cursor into a beachball and lags. </p>
  
  <p>Does anyone know why this happens or how to fix it without breaking the file up into smaller pieces?</p>