+++ /dev/null
-module test
-
-import StdEnv
-
-import Data.Functor
-import Control.Applicative
-import Control.Monad
-import Control.Monad.State
-
-import Text.Parsers.Simple.Core
-
-:: In a b = (:.) infix 0 a b
-
-:: Gram
- = Def (Gram -> In Gram Gram)
- | Def2 ((Gram,Gram) -> In (Gram, Gram) Gram)
- | Lit String
- | Int
- | (-.) infixr 2 Gram Gram
- | (|.) infix 1 Gram Gram
-:: Gast
- = INT Int
- | LIT String
- | BIN Gast Gast
-
-parseFromGram :: Gram -> Parser String Gast
-parseFromGram (Def g) = let (body :. gram) = g body in parseFromGram gram
-parseFromGram Int = INT o toInt <$> pSatisfy (\s->toString (toInt s) == s)
-parseFromGram (Lit i) = LIT <$> pSatisfy ((==)i)
-parseFromGram (a -. b) = BIN <$> parseFromGram a <*> parseFromGram b
-parseFromGram (a |. b) = parseFromGram a <|> parseFromGram b
-
-//Start = runParser (parseFromGram gram) [".","."]
-Start = parse (parseFromGram gram) ["5"]
-where
- gram =
- Def \lit = Int
- |. Lit "(" -. expr -. Lit ")"
- Def \fac = lit -. Lit "*" -. fac
- |. lit -. Lit "/" -. fac
- |. lit :.
- Def \expr= fac -. Lit "+" -. expr
- |. fac -. Lit "-" -. expr
- |. fac :.
- expr