title: C# parse filter string
body: <p>I need to parse following string,</p>
  
  <pre><code>var filter = "username eq \"john.smith\""
  </code></pre>
  
  <p>and  get,</p>
  
  <pre><code>var leftPart = "username"
  var operator = "eq"
  var rightPart = "john.smith"
  </code></pre>
  
  <p>What is the best way to do this?</p>
  
  <p>I need to parse complex queries like,</p>
  
  <pre><code>filter=userType eq "Employee" and emails.type eq "work"
  </code></pre>
  
  <p>Yeah, I looked into string split, regex, iterate by char. Is there a library to do these things? I am looking for a complex filter query parsing. I looked into Antlr, but unfortunately I cannot get it working .net core + VS2017.</p>