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gf-core/src/compiler/GF/Infra/CheckM.hs
2012-06-25 11:49:50 +00:00

88 lines
3.1 KiB
Haskell

----------------------------------------------------------------------
-- |
-- Module : CheckM
-- Maintainer : (Maintainer)
-- Stability : (stable)
-- Portability : (portable)
--
-- > CVS $Date: 2005/04/21 16:22:33 $
-- > CVS $Author: bringert $
-- > CVS $Revision: 1.5 $
--
-- (Description of the module)
-----------------------------------------------------------------------------
module GF.Infra.CheckM
(Check(..), CheckResult(..), Message, runCheck,
checkError, checkCond, checkWarn,
checkErr, checkIn, checkMap, checkMapRecover
) where
import GF.Data.Operations
import GF.Infra.Ident
import GF.Grammar.Grammar
import GF.Grammar.Printer
import qualified Data.Map as Map
import Text.PrettyPrint
type Message = Doc
data CheckResult a
= Fail [Message]
| Success a [Message]
newtype Check a = Check {unCheck :: Context -> [Message] -> CheckResult a}
instance Monad Check where
return x = Check (\ctxt msgs -> Success x msgs)
f >>= g = Check (\ctxt msgs -> case unCheck f ctxt msgs of
Success x msgs -> unCheck (g x) ctxt msgs
Fail msgs -> Fail msgs)
instance ErrorMonad Check where
raise s = checkError (text s)
handle f h = Check (\ctxt msgs -> case unCheck f ctxt msgs of
Success x msgs -> Success x msgs
Fail (msg:msgs) -> unCheck (h (render msg)) ctxt msgs)
checkError :: Message -> Check a
checkError msg = Check (\ctxt msgs -> Fail (msg : msgs))
checkCond :: Message -> Bool -> Check ()
checkCond s b = if b then return () else checkError s
-- | warnings should be reversed in the end
checkWarn :: Message -> Check ()
checkWarn msg = Check (\ctxt msgs -> Success () ((text "Warning:" <+> msg) : msgs))
runCheck :: Check a -> Err (a,String)
runCheck c =
case unCheck c [] [] of
Fail msgs -> Bad ( render (vcat (reverse msgs)))
Success v msgs -> Ok (v, render (vcat (reverse msgs)))
checkMap :: (Ord a) => (a -> b -> Check b) -> Map.Map a b -> Check (Map.Map a b)
checkMap f map = do xs <- mapM (\(k,v) -> do v <- f k v
return (k,v)) (Map.toList map)
return (Map.fromAscList xs)
checkMapRecover :: (Ord a) => (a -> b -> Check b) -> Map.Map a b -> Check (Map.Map a b)
checkMapRecover f mp = do
let xs = map (\ (k,v) -> (k,runCheck (f k v))) (Map.toList mp)
case [s | (_,Bad s) <- xs] of
ss@(_:_) -> checkError (text (unlines ss))
_ -> do
let (kx,ss) = unzip [((k,x),s) | (k, Ok (x,s)) <- xs]
checkWarn (text (unlines ss))
return (Map.fromAscList kx)
checkErr :: Err a -> Check a
checkErr (Ok x) = return x
checkErr (Bad err) = checkError (text err)
checkIn :: Doc -> Check a -> Check a
checkIn msg c = Check $ \ctxt msgs ->
case unCheck c ctxt [] of
Fail msgs' -> Fail ((msg $$ nest 3 (vcat (reverse msgs'))) : msgs)
Success v msgs' | null msgs' -> Success v msgs
| otherwise -> Success v ((msg $$ nest 3 (vcat (reverse msgs'))) : msgs)