# Kessel

Kessel is a reworking of clarsec to use contrib.monads instead of the home brewed monads in clarsec. I'd like to, in the future, build this into something that can handle any grammar without blowing up, using some memoization techniques I've read about in some papers, but we'll see if that ever happens.

## Usage

See the examples in kessel/examples.


## Caveats (unchanged from clarsec)

forward references are a mess. I tried to maintain the DSL as simple as possible. Imagine that "structureDef" and "comma" are two already existing
parsers, and "brackets" and "sepBy" are two combinators. I want to be able to write it like this:

  (def structure 
       (brackets (sepBy structureDef comma)))

however, clojures 'def' binding is strict and all the referenced vars have to be already defined, otherwise you get:

 Var example/structureDef is unbound.

I'm a clojure newbie, so I don't know exactly how to avoid this. I know only of two workarounds:

 1. use functions:   (defn structure [] (brackets (sepBy (structureDef) (comma))))
 2. use delay:       (def structure (delay (brackets (sepBy structureDef comma))))

I opted for the "delay", as it allowed me to avoid all those spurious parens, and retain the illusion of a parser DSL, and put the "delay" only where needed. (or everywhere
with a "defblabla" macro).

Unfortunately this required a small patch to Brandmeyer's monad library.

## Installation

lein jar

## License

http://www.apache.org/licenses/LICENSE-2.0.html