module IOEnv (
IOEnv, -- Instance of Monad
- -- Standard combinators, specialised
- returnM, thenM, thenM_, failM, failWithM,
- mappM, mappM_, mapSndM, sequenceM, sequenceM_,
- foldlM, foldrM,
- mapAndUnzipM, mapAndUnzip3M,
- checkM, ifM, zipWithM, zipWithM_,
+ -- Monad utilities
+ module MonadUtils,
+
+ -- Errors
+ failM, failWithM,
-- Getting at the environment
getEnv, setEnv, updEnv,
tryM, tryAllM, tryMostM, fixM,
-- I/O operations
- ioToIOEnv,
IORef, newMutVar, readMutVar, writeMutVar, updMutVar
) where
#include "HsVersions.h"
import Panic ( try, tryUser, tryMost, Exception(..) )
-import Data.IORef ( IORef, newIORef, readIORef, writeIORef )
+import Data.IORef ( IORef, newIORef, readIORef, writeIORef, modifyIORef )
import System.IO.Unsafe ( unsafeInterleaveIO )
import System.IO ( fixIO )
-
+import MonadUtils
----------------------------------------------------------------------
-- Defining the monad type
unIOEnv (IOEnv m) = m
instance Monad (IOEnv m) where
- (>>=) = thenM
- (>>) = thenM_
- return = returnM
- fail s = failM -- Ignore the string
+ (>>=) = thenM
+ (>>) = thenM_
+ return = returnM
+ fail s = failM -- Ignore the string
+
+instance Applicative (IOEnv m) where
+ pure = returnM
+ IOEnv f <*> IOEnv x = IOEnv (\ env -> f env <*> x env )
instance Functor (IOEnv m) where
- fmap f (IOEnv m) = IOEnv (\ env -> fmap f (m env))
+ fmap f (IOEnv m) = IOEnv (\ env -> fmap f (m env))
returnM :: a -> IOEnv env a
returnM a = IOEnv (\ env -> return a)
---------------------------
tryM :: IOEnv env r -> IOEnv env (Either Exception r)
--- Reflect UserError exceptions into IOEnv monad
+-- Reflect UserError exceptions (only) into IOEnv monad
+-- Other exceptions are not caught; they are simply propagated as exns
+--
-- The idea is that errors in the program being compiled will give rise
-- to UserErrors. But, say, pattern-match failures in GHC itself should
-- not be caught here, else they'll be reported as errors in the program
-- Accessing input/output
----------------------------------------------------------------------
-ioToIOEnv :: IO a -> IOEnv env a
-ioToIOEnv io = IOEnv (\ env -> io)
+instance MonadIO (IOEnv env) where
+ liftIO io = IOEnv (\ env -> io)
newMutVar :: a -> IOEnv env (IORef a)
-newMutVar val = IOEnv (\ env -> newIORef val)
+newMutVar val = liftIO (newIORef val)
writeMutVar :: IORef a -> a -> IOEnv env ()
-writeMutVar var val = IOEnv (\ env -> writeIORef var val)
+writeMutVar var val = liftIO (writeIORef var val)
readMutVar :: IORef a -> IOEnv env a
-readMutVar var = IOEnv (\ env -> readIORef var)
+readMutVar var = liftIO (readIORef var)
-updMutVar :: IORef a -> (a->a) -> IOEnv env ()
-updMutVar var upd_fn = IOEnv (\ env -> do { v <- readIORef var; writeIORef var (upd_fn v) })
+updMutVar :: IORef a -> (a -> a) -> IOEnv env ()
+updMutVar var upd = liftIO (modifyIORef var upd)
----------------------------------------------------------------------
{-# INLINE getEnv #-}
getEnv = IOEnv (\ env -> return env)
+-- | Perform a computation with a different environment
setEnv :: env' -> IOEnv env' a -> IOEnv env a
{-# INLINE setEnv #-}
setEnv new_env (IOEnv m) = IOEnv (\ env -> m new_env)
+-- | Perform a computation with an altered environment
updEnv :: (env -> env') -> IOEnv env' a -> IOEnv env a
{-# INLINE updEnv #-}
updEnv upd (IOEnv m) = IOEnv (\ env -> m (upd env))
-- (for efficiency)
----------------------------------------------------------------------
-mappM :: (a -> IOEnv env b) -> [a] -> IOEnv env [b]
-mappM_ :: (a -> IOEnv env b) -> [a] -> IOEnv env ()
-mapSndM :: (b -> IOEnv env c) -> [(a,b)] -> IOEnv env [(a,c)]
- -- Funny names to avoid clash with Prelude
-sequenceM :: [IOEnv env a] -> IOEnv env [a]
-sequenceM_ :: [IOEnv env a] -> IOEnv env ()
-foldlM :: (a -> b -> IOEnv env a) -> a -> [b] -> IOEnv env a
-foldrM :: (b -> a -> IOEnv env a) -> a -> [b] -> IOEnv env a
-mapAndUnzipM :: (a -> IOEnv env (b,c)) -> [a] -> IOEnv env ([b],[c])
-mapAndUnzip3M :: (a -> IOEnv env (b,c,d)) -> [a] -> IOEnv env ([b],[c],[d])
-checkM :: Bool -> IOEnv env a -> IOEnv env () -- Perform arg if bool is False
-ifM :: Bool -> IOEnv env a -> IOEnv env () -- Perform arg if bool is True
-
-mappM f [] = return []
-mappM f (x:xs) = do { r <- f x; rs <- mappM f xs; return (r:rs) }
-
-mapSndM f [] = return []
-mapSndM f ((a,b):xs) = do { c <- f b; rs <- mapSndM f xs; return ((a,c):rs) }
-
-mappM_ f [] = return ()
-mappM_ f (x:xs) = f x >> mappM_ f xs
-
-zipWithM :: (a -> b -> IOEnv env c) -> [a] -> [b] -> IOEnv env [c]
-zipWithM f [] bs = return []
-zipWithM f as [] = return []
-zipWithM f (a:as) (b:bs) = do { r <- f a b; rs <- zipWithM f as bs; return (r:rs) }
-
-zipWithM_ :: (a -> b -> IOEnv env c) -> [a] -> [b] -> IOEnv env ()
-zipWithM_ f [] bs = return ()
-zipWithM_ f as [] = return ()
-zipWithM_ f (a:as) (b:bs) = do { f a b; zipWithM_ f as bs }
-
-sequenceM [] = return []
-sequenceM (x:xs) = do { r <- x; rs <- sequenceM xs; return (r:rs) }
-
-sequenceM_ [] = return ()
-sequenceM_ (x:xs) = do { x; sequenceM_ xs }
-
-foldlM k z [] = return z
-foldlM k z (x:xs) = do { r <- k z x; foldlM k r xs }
-
-foldrM k z [] = return z
-foldrM k z (x:xs) = do { r <- foldrM k z xs; k x r }
-
-mapAndUnzipM f [] = return ([],[])
-mapAndUnzipM f (x:xs) = do { (r,s) <- f x;
- (rs,ss) <- mapAndUnzipM f xs;
- return (r:rs, s:ss) }
-
-mapAndUnzip3M f [] = return ([],[], [])
-mapAndUnzip3M f (x:xs) = do { (r,s,t) <- f x;
- (rs,ss,ts) <- mapAndUnzip3M f xs;
- return (r:rs, s:ss, t:ts) }
-
-checkM True err = return ()
-checkM False err = do { err; return () }
-
-ifM True do_it = do { do_it; return () }
-ifM False do_it = return ()
+{-# -- SPECIALIZE mapM :: (a -> IOEnv env b) -> [a] -> IOEnv env [b] #-}
+{-# -- SPECIALIZE mapM_ :: (a -> IOEnv env b) -> [a] -> IOEnv env () #-}
+{-# -- SPECIALIZE mapSndM :: (b -> IOEnv env c) -> [(a,b)] -> IOEnv env [(a,c)] #-}
+{-# -- SPECIALIZE sequence :: [IOEnv env a] -> IOEnv env [a] #-}
+{-# -- SPECIALIZE sequence_ :: [IOEnv env a] -> IOEnv env () #-}
+{-# -- SPECIALIZE foldlM :: (a -> b -> IOEnv env a) -> a -> [b] -> IOEnv env a #-}
+{-# -- SPECIALIZE foldrM :: (b -> a -> IOEnv env a) -> a -> [b] -> IOEnv env a #-}
+{-# -- SPECIALIZE mapAndUnzipM :: (a -> IOEnv env (b,c)) -> [a] -> IOEnv env ([b],[c]) #-}
+{-# -- SPECIALIZE mapAndUnzip3M :: (a -> IOEnv env (b,c,d)) -> [a] -> IOEnv env ([b],[c],[d]) #-}
+{-# -- SPECIALIZE zipWithM :: (a -> b -> IOEnv env c) -> [a] -> [b] -> IOEnv env [c] #-}
+{-# -- SPECIALIZE zipWithM_ :: (a -> b -> IOEnv env c) -> [a] -> [b] -> IOEnv env () #-}
+{-# -- SPECIALIZE anyM :: (a -> IOEnv env Bool) -> [a] -> IOEnv env Bool #-}
+{-# -- SPECIALIZE when :: Bool -> IOEnv env a -> IOEnv env () #-}
+{-# -- SPECIALIZE unless :: Bool -> IOEnv env a -> IOEnv env () #-}
projects / ghc-hetmet.git / blobdiff