diff options
Diffstat (limited to 'compiler/types/TyCoRep.hs')
| -rw-r--r-- | compiler/types/TyCoRep.hs | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/compiler/types/TyCoRep.hs b/compiler/types/TyCoRep.hs index 588963d012..9323e23de6 100644 --- a/compiler/types/TyCoRep.hs +++ b/compiler/types/TyCoRep.hs @@ -34,6 +34,7 @@ module TyCoRep ( UnivCoProvenance(..), CoercionHole(..), coHoleCoVar, CoercionN, CoercionR, CoercionP, KindCoercion, + MCoercion, -- * Functions over types mkTyConTy, mkTyVarTy, mkTyVarTys, @@ -857,6 +858,10 @@ type CoercionR = Coercion -- always representational type CoercionP = Coercion -- always phantom type KindCoercion = CoercionN -- always nominal +-- | A semantically more meaningful type to represent what may or may not be a +-- useful 'Coercion'. +data MCoercion = MRefl | MCo Coercion + {- Note [Refl invariant] ~~~~~~~~~~~~~~~~~~~~~ |