Writing a parser by hand can be a bit repetitive, but it's actually not that bad with a bit of experience. Many production parsers are written by hand.

Here's a good article about parsing expressions: http://journal.stuffwithstuff.com/2011/03/19/pratt-parsers-e...

And my half-baked explanation which may not make sense unless you've already tried it: https://plus.google.com/+BrianSlesinsky/posts/hMr5NEnQcxC