Moved Err definition to GF.Data.ErrM from GF.Data.Operations. This means the GF-embed does not have to include GF.Data.Operations.

src/GF/Data/ErrM.hs

@@ -12,9 +12,27 @@
 -- hack for BNFC generated files. AR 21/9/2003
 -----------------------------------------------------------------------------
 
-module GF.Data.ErrM (
+module GF.Data.ErrM (Err(..)) where
-		     module GF.Data.Operations
-	    ) where
 
-import GF.Data.Operations (Err(..))
+import Control.Monad (MonadPlus(..))
 
+-- | like @Maybe@ type with error msgs
+data Err a = Ok a | Bad String
+  deriving (Read, Show, Eq)
+
+instance Monad Err where
+  return      = Ok
+  fail        = Bad
+  Ok a  >>= f = f a
+  Bad s >>= f = Bad s
+
+-- | added 2\/10\/2003 by PEB
+instance Functor Err where
+  fmap f (Ok a) = Ok (f a)
+  fmap f (Bad s) = Bad s
+
+-- | added by KJ
+instance MonadPlus Err where
+    mzero = Bad "error (no reason given)"
+    mplus (Ok a)  _ = Ok a
+    mplus (Bad s) b = b

src/GF/Data/Operations.hs

@@ -80,6 +80,8 @@ import Data.List (nub, sortBy, sort, deleteBy, nubBy)
 --import Data.FiniteMap
 import Control.Monad (liftM,liftM2, MonadPlus, mzero, mplus)
 
+import GF.Data.ErrM
+
 infixr 5 +++
 infixr 5 ++-
 infixr 5 ++++
@@ -94,27 +96,6 @@ onSnd f (x, y) = (x, f y)
 
 -- the Error monad
 
--- | like @Maybe@ type with error msgs
-data Err a = Ok a | Bad String
-  deriving (Read, Show, Eq)
-
-instance Monad Err where
-  return      = Ok
-  fail        = Bad
-  Ok a  >>= f = f a
-  Bad s >>= f = Bad s
-
--- | added 2\/10\/2003 by PEB
-instance Functor Err where
-  fmap f (Ok a) = Ok (f a)
-  fmap f (Bad s) = Bad s
-
--- | added by KJ
-instance MonadPlus Err where
-    mzero = Bad "error (no reason given)"
-    mplus (Ok a)  _ = Ok a
-    mplus (Bad s) b = b
-
 -- | analogue of @maybe@
 err :: (String -> b) -> (a -> b) -> Err a -> b 
 err d f e = case e of