Fix warnings in 16 modules, mostly forward compatibility warnings from GHC 7.8

src/compiler/GF/Infra/CheckM.hs

@@ -28,7 +28,8 @@ import qualified Data.Map as Map
 import GF.Text.Pretty
 import System.FilePath(makeRelative)
 import Control.Parallel.Strategies(parList,rseq,using)
-import Control.Monad(liftM)
+import Control.Monad(liftM,ap)
+import Control.Applicative(Applicative(..))
 
 type Message = Doc
 type Error   = Message
@@ -50,6 +51,10 @@ instance Monad Check where
                  (ws,Success x) -> unCheck (g x) {-ctxt-} ws
                  (ws,Fail msg)  -> (ws,Fail msg)
 
+instance Applicative Check where
+  pure = return
+  (<*>) = ap
+
 instance ErrorMonad Check where
   raise s = checkError (pp s)
   handle f h = handle' f (h . render)

src/compiler/GF/Infra/SIO.hs

@@ -19,10 +19,11 @@ module GF.Infra.SIO(
        restricted,restrictedSystem
   ) where
 import Prelude hiding (putStrLn,print)
-import Control.Monad(liftM)
+import Control.Applicative(Applicative(..))
+import Control.Monad(liftM,ap)
 import System.IO(hPutStrLn,hFlush,stdout)
 import GF.System.Catch(try)
-import System.Cmd(system)
+import System.Process(system)
 import System.Environment(getEnv)
 import Control.Concurrent.Chan(newChan,writeChan,getChanContents)
 import qualified System.CPUTime as IO(getCPUTime)
@@ -39,6 +40,10 @@ newtype SIO a = SIO {unS::PutStrLn->IO a}
 
 instance Functor SIO where fmap = liftM
 
+instance Applicative SIO where
+  pure = return
+  (<*>) = ap
+
 instance Monad SIO where
   return x = SIO (const (return x))
   SIO m1 >>= xm2 = SIO $ \ h -> m1 h >>= \ x -> unS (xm2 x) h

src/compiler/GF/Infra/UseIO.hs

@@ -31,6 +31,7 @@ import System.Exit
 import System.CPUTime
 --import System.Cmd
 import Text.Printf
+import Control.Applicative(Applicative(..))
 import Control.Monad
 import Control.Monad.Trans(MonadIO(..))
 import Control.Exception(evaluate)
@@ -150,6 +151,10 @@ instance ErrorMonad IOE where
 
 instance Functor IOE where fmap = liftM
 
+instance Applicative IOE where
+  pure = return
+  (<*>) = ap
+
 instance  Monad IOE where
   return a    = ioe (return (return a))
   IOE c >>= f = IOE $ do