5 files changed, 21 insertions, 22 deletions

diff --git a/events/events.cabal b/events/events.cabal
index 4ab12fd..390f062 100644
--- a/events/events.cabal
+++ b/events/events.cabal
@@ -45,4 +45,5 @@ executable events
                      , attoparsec >=0.13.0.2 && <1
                      , exceptions >=0.8.3 && <1
   hs-source-dirs:      src
-  default-language:    Haskell2010
\ No newline at end of file
+  default-language:    Haskell2010
+  ghc-options:         -Wall
\ No newline at end of file
diff --git a/events/src/Events/Spec.hs b/events/src/Events/Spec.hs
index 734a2dd..8b82873 100644
--- a/events/src/Events/Spec.hs
+++ b/events/src/Events/Spec.hs
@@ -1,5 +1,5 @@
 module Events.Spec
-       ( Spec, Expr(..), Val(..), Bindable(..), Elem(..)
+       ( Spec, Expr(..), Val, Bindable(..), Elem(..)
        , module Events.Spec.Parse
        , module Events.Spec.Eval
        ) where
diff --git a/events/src/Events/Spec/Eval.hs b/events/src/Events/Spec/Eval.hs
index fdc18c8..a9c16de 100644
--- a/events/src/Events/Spec/Eval.hs
+++ b/events/src/Events/Spec/Eval.hs
@@ -10,12 +10,13 @@ shift :: forall m ts2 t x. Expr m ts2 x -> Expr m (t ': ts2) x
 shift = shift' LZ
   where
     -- shift' :: forall ts1 ts2 t x. Length ts1 -> Expr (ts1 ++ ts2) x -> Expr (ts1 ++ t ': ts2) x
-    shift' :: forall ts1 x. Length ts1 -> Expr m (ts1 ++ ts2) x -> Expr m (ts1 ++ t ': ts2) x
+    shift' :: forall ts1 y. Length ts1 -> Expr m (ts1 ++ ts2) y -> Expr m (ts1 ++ t ': ts2) y
     shift'  LZ    (EPri f)   = EPri $ const (EPri f)
     shift' (LS l) (EPri f)   = EPri $ shift' l . f
     shift'  l     (EVar v)   = EVar $ shiftElem l v
     shift'  l     (ELam b)   = ELam $ shift' (LS l) b
     shift'  l     (EApp f x) = EApp (shift' l f) (shift' l x)
+    shift'  l     (EVal _)   = undefined
   
     shiftElem :: forall ts1 u. Length ts1 -> Elem u (ts1 ++ ts2) -> Elem u (ts1 ++ t ': ts2)
     shiftElem LZ e = ES e
@@ -24,18 +25,21 @@ shift = shift' LZ
     
 
 beta = flip beta' LZ
-beta' :: forall m ts1 ts2 s t. Expr m ts2 s -> Length ts1 -> Expr m (ts1 ++ s ': ts2) t -> Expr m (ts1 ++ ts2) t
-beta' e  LZ    (EPri f)      = EApp (ELam (EPri f)) e
-beta' e (LS l) (EPri f)      = EPri (beta' e l . f)
-beta' e  LZ    (EVar  EZ   ) = e
-beta' _  LZ    (EVar (ES v)) = EVar v
-beta' _ (LS _) (EVar  EZ   ) = EVar EZ
-beta' e (LS l) (EVar (ES v)) = shift $ beta' e l (EVar v)
-beta' e  l     (ELam b)      = ELam $ beta' e (LS l) b
-beta' e  l     (EApp f a)    = EApp (beta' e l f) (beta' e l a)
+  where
+    beta' :: forall m ts1 ts2 s t. Expr m ts2 s -> Length ts1 -> Expr m (ts1 ++ s ': ts2) t -> Expr m (ts1 ++ ts2) t
+    beta' e  LZ    (EPri f)      = EApp (ELam (EPri f)) e
+    beta' e (LS l) (EPri f)      = EPri (beta' e l . f)
+    beta' e  LZ    (EVar  EZ   ) = e
+    beta' _  LZ    (EVar (ES v)) = EVar v
+    beta' _ (LS _) (EVar  EZ   ) = EVar EZ
+    beta' e (LS l) (EVar (ES v)) = shift $ beta' e l (EVar v)
+    beta' e  l     (ELam b)      = ELam $ beta' e (LS l) b
+    beta' e  l     (EApp f a)    = EApp (beta' e l f) (beta' e l a)
+    beta' _  l     (EVal _)      = undefined
 
 evalExpr :: Expr m '[] t -> Val m t
 evalExpr (EVal a)                 = a
 evalExpr (ELam a)                 = a
 evalExpr (EApp (ELam (EPri f)) a) = evalExpr . f $ evalExpr a
 evalExpr (EApp f a)               = evalExpr $ beta a (evalExpr f)
+evalExpr (EVar _)                 = error "EVar was given bottom"
diff --git a/events/src/Events/Spec/Types.hs b/events/src/Events/Spec/Types.hs
index af99f55..d9d1ef1 100644
--- a/events/src/Events/Spec/Types.hs
+++ b/events/src/Events/Spec/Types.hs
@@ -4,12 +4,12 @@
 
 module Events.Spec.Types
   ( Expr(..)
-  , Val(..)
+  , Val
   , Bindable(..)
   , Spec
   , Elem(..)
   , Length(..)
-  , type (++)(..)
+  , type (++)
   , module Events.Types
   ) where
 
diff --git a/events/src/Events/Types/NDT.hs b/events/src/Events/Types/NDT.hs
index a417029..c37d47c 100644
--- a/events/src/Events/Types/NDT.hs
+++ b/events/src/Events/Types/NDT.hs
@@ -12,22 +12,16 @@ module Events.Types.NDT
 
 import Data.Monoid
 import Data.Foldable (foldr)
-import Data.Maybe
-import Data.Either
 import Data.Bool (bool)
 
 import Control.Applicative (Alternative)
 import qualified Control.Applicative as Alt (Alternative(..))
 import Control.Monad
-import Control.Monad.Identity
 
 import Control.Monad.Trans
 import Control.Monad.Reader (MonadReader(..))
-import Control.Monad.Trans.Maybe
 import Control.Monad.Catch (MonadThrow(..))
 
-import Debug.Trace
-
 data NDT m a where
   NDTBind :: NDT m a -> (a -> NDT m b) -> NDT m b
   NDTCons :: m (Maybe (a, NDT m a)) -> NDT m a
@@ -37,7 +31,7 @@ instance Functor m => Functor (NDT m) where
   fmap f (NDTCons x) = NDTCons $ fmap f' x
     where
       f' Nothing = Nothing
-      f' (Just (x, xs)) = Just (f x, fmap f xs)
+      f' (Just (x', xs)) = Just (f x', fmap f xs)
 
 instance Applicative m => Applicative (NDT m) where
   pure x = NDTCons . pure $ Just (x, empty)
@@ -49,7 +43,7 @@ instance Applicative m => Monad (NDT m) where
 
 instance Monad m => Monoid (NDT m a) where
   mempty = empty
-  mappend (NDTCons x) y'@(NDTCons y) = NDTCons $ maybe y (\(x, xs) -> return $ Just (x, xs <> y')) =<< x
+  mappend (NDTCons x) y'@(NDTCons y) = NDTCons $ maybe y (\(x', xs) -> return $ Just (x', xs <> y')) =<< x
   mappend (NDTBind x f) (NDTBind y g) = NDTBind (fmap Left x <> fmap Right y) (either f g)
   mappend x@(NDTBind _ _) y = x <> NDTBind y return
   mappend x y@(NDTBind _ _) = NDTBind x return <> y