title: Should I throw an exception on user input errors?
body: <p>I'm writing a user input library to easily manage the dynamic creation of forms for asking users for data.</p>
  
  <p>I wanted to make the end developer have to 'think' about the bare minimum, so I went with having them throw exceptions instead of returning 'true' or 'false' and remembering to handle the return value etc.</p>
  
  <p>In reality, it's worked out really well. Throwing exceptions has also given me a side benefit of being able to automatically record user errors in a log, all for 'free' as the creation of the exception causes the logging to be done.</p>
  
  <p>Having said all of that, I was wondering if this is really 'against best practices'? Should I have kept exceptions only for times when I didn't even expect user input error, or is it OK to say "the data from the user has a problem... that's an exception"?</p>
  
  <p>Any thoughts?</p>