I ♡ attoparsec

nginx.hs

{-# LANGUAGE OverloadedStrings, DeriveDataTypeable, TemplateHaskell, DeriveGeneric #-}

import Data.Text(Text)
import qualified Data.Text as Text
import qualified Data.Text.IO as Text
import Data.Attoparsec.Text
import Control.Applicative
import Control.Monad
import Data.Aeson(encode,ToJSON)
import Data.Typeable(Typeable)
import Data.Data(Data)
import qualified Data.ByteString.Lazy.Char8 as BS
import GHC.Generics

data Directive = Directive { name :: Text, value :: Text } | Block { name :: Text, directives :: [Directive] } deriving (Show,Data,Typeable,Generic)
instance ToJSON Directive

type Config = [Directive]

config :: Parser Config
config = many directive <* endOfInput

directiveName :: Parser Text
directiveName = Text.pack <$> some (letter <|> char '_')

directive = blockDirective <|> simpleDirective

blockDirective :: Parser Directive
blockDirective = Block <$> (directiveName <* skipSpace) <*> (char '{' *> skipSpace *> many directive <* char '}') <* endOfLine <* skipSpace

simpleDirective :: Parser Directive
simpleDirective = Directive <$> (directiveName <* skipSpace) <*> takeWhile1 (/= ';') <* char ';' <* endOfLine <* skipSpace

main = Text.readFile "nginx/nginx.conf" >>= \s -> BS.putStrLn $ encode $ parseOnly config s