I have just uploaded to Hackage the Pinchot library: https://hackage.haskell.org/package/pinchot I also have a pull request to get it into Stackage so hopefully it should be there in a few days as well. Pinchot provides a simple monadic language that you use to describe a context-free grammar. Using this language you build a value that represents your grammar. Then, using this value and Template Haskell, you can automatically generate a complete set of data types that correspond to the rules in your context-free grammar. You also use Template Haskell to generate an Earley grammar for your language, using the Haskell Earley library: https://hackage.haskell.org/package/Earley Unlike parsers such as Parsec and Happy, Earley parses all context-free grammars, regardless of the amount of necessary look-ahead or the presence of left recursion. Earley does not, however, parse context-sensitive grammars. Pinchot is documented and comes with several examples. It passes several simple tests but it has not yet been used in anger. I wrote Pinchot because I was excited to see Earley when it was released. Finally we had a parser that would simply parse context-free grammars. Give a grammar, get a parser. Parsec and its ilk, on the other hand, are libraries allowing you to write a recursive-descent parser by hand. That's useful, but if you know you have a context-free grammar it's easier to use a tool tailored to that. So when using Earley I found myself writing the data types and then writing the Earley grammar specification. This was a rote process ripe for automation.