title: proper regex to tokenize sentence with leading dash
body: <p>Here is the regex i'm using for tokenizer: <code>[^a-zA-Z\'-]+</code></p>
  
  <p>However, if I want to apply it to sentence like this:
  <code>-This is a test. -yes, it's a test for self-consciousness</code>
  The result would be <code>['-This', 'is', 'a', 'test', '-yes', "it's", 'a', 'test', 'for', 'self-consciousness']</code> where there is leading <code>-</code> ahead of <code>This</code> and <code>yes</code>. Is there gonna be a way to eliminate the leading <code>-</code>? Maybe some modification on the regex i'm using?</p>