Then it's not a string, it's a ReQL query object. Same way a Django model instance isn't a string. Your comparison seems way too artificially made up towards Rethink, so much so that it discredits itself.
Imagine me saying "here's a SQL string, let's see which database can execute it more easily, Rethink or Postgres. Hint: Start with writing a parser to convert it to ReQL".
Imagine me saying "here's a SQL string, let's see which database can execute it more easily, Rethink or Postgres. Hint: Start with writing a parser to convert it to ReQL".