Find file
Fetching contributors…
Cannot retrieve contributors at this time
45 lines (25 sloc) 1.63 KB
# clarsec
clarsec is an attempt to port haskell parsec to clojure
This library is inspired on http://kotka.de/projects/clojure/parser.html and uses the Meikel Brandmeyer's "monad" library (slightly adapted), as I didn't understand how the clojure contrib monad
library works.
## Usage
there is an example parser which I ported straight from a Haskell Parsec code.
Basically, you should be able to write the examples on http://kotka.de/projects/clojure/parser.html.
The library comes with a small number of basic combinators. I hope it will be useful.
## Caveats
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
leim jar
## License
http://www.apache.org/licenses/LICENSE-2.0.html