2 files changed, 16 insertions, 12 deletions

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