more dumb typos, i really need to learn the ghci fast type checking dev work flow for ghc

also added a note about an idea i'm probably gonna do tomorrow

4 files changed, 12 insertions, 5 deletions

diff --git a/compiler/coreSyn/CoreLint.hs b/compiler/coreSyn/CoreLint.hs
index 10cb022b18..b587196159 100644
--- a/compiler/coreSyn/CoreLint.hs
+++ b/compiler/coreSyn/CoreLint.hs
@@ -1691,7 +1691,7 @@ lintCoercion :: OutCoercion -> LintM (LintedKind, LintedKind, LintedType, Linted
 -- See Note [GHC Formalism]
 lintCoercion (ErasedCoercion role lty rty)
   = do { kl <- lintType lty ;
-         kr <- lintType rty
+         kr <- lintType rty ;
          return (kl,kr,lty,rty,role)
        }
 lintCoercion (Refl ty)
diff --git a/compiler/iface/TcIface.hs b/compiler/iface/TcIface.hs
index 818745775a..18d62f5b88 100644
--- a/compiler/iface/TcIface.hs
+++ b/compiler/iface/TcIface.hs
@@ -1215,6 +1215,9 @@ tcIfaceCo = go
     go_mco IfaceMRefl    = pure MRefl
     go_mco (IfaceMCo co) = MCo <$> (go co)
 
+    go (IfaceErased r ltyi rtyi)
+                                 = ErasedCoercion r  <$>(tcIfaceType ltyi)
+                                                     <*>(tcIfaceType rtyi)
     go (IfaceReflCo t)           = Refl <$> tcIfaceType t
     go (IfaceGReflCo r t mco)    = GRefl r <$> tcIfaceType t <*> go_mco mco
     go (IfaceFunCo r c1 c2)      = mkFunCo r <$> go c1 <*> go c2
diff --git a/compiler/iface/ToIface.hs b/compiler/iface/ToIface.hs
index 62b091c0af..c23985d89d 100644
--- a/compiler/iface/ToIface.hs
+++ b/compiler/iface/ToIface.hs
@@ -265,7 +265,7 @@ toIfaceCoercionX fr co
     go_mco MRefl     = IfaceMRefl
     go_mco (MCo co)  = IfaceMCo $ go co
 
-    go (ErasedCoercion r lty rty)     = IfaceErased r lty rty
+    go (ErasedCoercion r lty rty)     = IfaceErased r (toIfaceType lty) (toIfaceType rty)
     go (Refl ty)            = IfaceReflCo (toIfaceTypeX fr ty)
     go (GRefl r ty mco)     = IfaceGReflCo r (toIfaceTypeX fr ty) (go_mco mco)
     go (CoVarCo cv)
diff --git a/compiler/simplCore/CoreEraseCoercionProofs.hs b/compiler/simplCore/CoreEraseCoercionProofs.hs
index cf498d5e8b..baa0695cb7 100644
--- a/compiler/simplCore/CoreEraseCoercionProofs.hs
+++ b/compiler/simplCore/CoreEraseCoercionProofs.hs
@@ -3,6 +3,7 @@ module CoreEraseCoercionProofs (eraseCoercionProgram,coreProgramEraseCoercionPro
 import GhcPrelude
 
 import CoreSyn
+import Pair
 import HscTypes         ( ModGuts(..) )
 import Coercion
 import CoreMonad        ( CoreM )
@@ -35,13 +36,16 @@ coreExprEraseProof (Lam   v e) =  Lam v $ coreExprEraseProof e
 coreExprEraseProof (Let   binder bod) = Let (eraseBinders binder) (coreExprEraseProof bod)
 coreExprEraseProof (Case  scrut v ty alts  )=
     Case (coreExprEraseProof scrut) v ty (map eraseAltPfs alts)
+    --- TODO : add mrefl and refl cases,
+    --- that should suffice to prevent regresions vs current ghc
 coreExprEraseProof (Cast  e co ) = Cast (coreExprEraseProof e) (ErasedCoercion role lty rty )
   where
-    (Pair lty rty,role) = coercionKindRole
+    (Pair lty rty,role) = coercionKindRole co
 coreExprEraseProof (Tick  tick e)= Tick tick (coreExprEraseProof e)
 coreExprEraseProof (Type  t) = Type t
-coreExprEraseProof (Coercion _)= Coercion ErasedCoercion
-
+coreExprEraseProof (Coercion co )=  Coercion (ErasedCoercion role lty rty )
+  where
+    (Pair lty rty,role) = coercionKindRole co
 eraseAltPfs :: CoreAlt -> CoreAlt
 eraseAltPfs (con, vars, body) = (con,vars,coreExprEraseProof body)