Require Import HaskCoreVars.
Require Import HaskCoreTypes.
-(* TO DO: mark the TyCon used for hetmet as a "type family" so GHC keeps it fully-applied-at-all-times *)
Variable tyConToCoreTyCon : TyCon -> CoreTyCon. Extract Inlined Constant tyConToCoreTyCon => "(\x -> x)".
Variable tyFunToCoreTyCon : TyFun -> CoreTyCon. Extract Inlined Constant tyFunToCoreTyCon => "(\x -> x)".
Coercion tyConToCoreTyCon : TyCon >-> CoreTyCon.
right; intro; apply n; inversion H; subst; auto.
Defined.
-(* TO DO: write a proper EqDecidable instance for WeakType and then move the rest of this into HaskWeakToCore *)
+(* a WeakCoerVar just wraps a CoreVar and tags it with the pair of types amongst which it coerces *)
+Inductive WeakCoerVar := weakCoerVar : CoreVar -> Kind -> WeakType -> WeakType -> WeakCoerVar.
+
+Inductive WeakCoercion : Type :=
+| WCoVar : WeakCoerVar -> WeakCoercion (* g *)
+| WCoType : WeakType -> WeakCoercion (* τ *)
+| WCoApp : WeakCoercion -> WeakCoercion -> WeakCoercion (* γ γ *)
+| WCoAppT : WeakCoercion -> WeakType -> WeakCoercion (* γ@v *)
+| WCoAll : Kind -> (WeakTypeVar -> WeakCoercion) -> WeakCoercion (* ∀a:κ.γ *)
+| WCoSym : WeakCoercion -> WeakCoercion (* sym *)
+| WCoComp : WeakCoercion -> WeakCoercion -> WeakCoercion (* ◯ *)
+| WCoLeft : WeakCoercion -> WeakCoercion (* left *)
+| WCoRight : WeakCoercion -> WeakCoercion (* right *)
+| WCoUnsafe : WeakType -> WeakType -> WeakCoercion (* unsafe *)
+(*| WCoCFApp : ∀ n, CoFunConst n -> vec WeakCoercion n -> WeakCoercion (* C γⁿ *)*)
+(*| WCoTFApp : ∀ n, TyFunConst n -> vec WeakCoercion n -> WeakCoercion (* S_n γⁿ *)*)
+.
+
+Variable Prelude_error : forall {A}, string -> A. Extract Inlined Constant Prelude_error => "Prelude.error".
+Fixpoint weakCoercionTypes (wc:WeakCoercion) : WeakType * WeakType :=
+match wc with
+| WCoVar (weakCoerVar _ _ t1 t2) => (t1,t2)
+| WCoType t => Prelude_error "FIXME WCoType"
+| WCoApp c1 c2 => Prelude_error "FIXME WCoApp"
+| WCoAppT c t => Prelude_error "FIXME WCoAppT"
+| WCoAll k f => Prelude_error "FIXME WCoAll"
+| WCoSym c => let (t2,t1) := weakCoercionTypes c in (t1,t2)
+| WCoComp c1 c2 => Prelude_error "FIXME WCoComp"
+| WCoLeft c => Prelude_error "FIXME WCoLeft"
+| WCoRight c => Prelude_error "FIXME WCoRight"
+| WCoUnsafe t1 t2 => (t1,t2)
+end.
+
Variable ModalBoxTyCon : TyCon. Extract Inlined Constant ModalBoxTyCon => "TysWiredIn.hetMetCodeTypeTyCon".
Variable ArrowTyCon : TyCon. Extract Constant ArrowTyCon => "Type.funTyCon".
-(* if this is a (WAppTy (WAppTy ... (WTyCon tc) .. ) .. ), return (tc,[...]) *)
-Fixpoint isTyConApp (wt:WeakType)(acc:list WeakType) : ??(TyCon * list WeakType) :=
- match wt with
- | WTyCon tc => Some (tc,acc)
- | WAppTy t1 t2 => isTyConApp t1 (t2::acc)
- | _ => None
- end.
-
-(* messy first-order NON-CAPTURE-AVOIDING substitution on WeakType's *)
-Fixpoint replaceWeakTypeVar (te:WeakType)(tv:WeakTypeVar)(tsubst:WeakType) : WeakType :=
- match te with
- | WTyVarTy tv' => if eqd_dec tv tv' then tsubst else te
- | WAppTy t1 t2 => WAppTy (replaceWeakTypeVar t1 tv tsubst) (replaceWeakTypeVar t2 tv tsubst)
- | WForAllTy tv' t => if eqd_dec tv tv' then te else WForAllTy tv' (replaceWeakTypeVar t tv tsubst)
- | WCoFunTy t1 t2 t => WCoFunTy (replaceWeakTypeVar t1 tv tsubst)
- (replaceWeakTypeVar t2 tv tsubst) (replaceWeakTypeVar t tv tsubst)
- | WIParam ip ty => WIParam ip (replaceWeakTypeVar ty tv tsubst)
- | WClassP c lt => WClassP c ((fix replaceCoreDistinctList (lt:list WeakType) :=
- match lt with
- | nil => nil
- | h::t => (replaceWeakTypeVar h tv tsubst)::(replaceCoreDistinctList t)
- end) lt)
- | WTyFunApp tc lt => WTyFunApp tc ((fix replaceCoreDistinctList (lt:list WeakType) :=
- match lt with
- | nil => nil
- | h::t => (replaceWeakTypeVar h tv tsubst)::(replaceCoreDistinctList t)
- end) lt)
- | WTyCon tc => WTyCon tc
- | WFunTyCon => WFunTyCon
- | WModalBoxTyCon => WModalBoxTyCon
- end.
-
-(* we try to normalize the representation of a type as much as possible before feeding it back to GHCs type-comparison function *)
-Definition normalizeWeakType (wt:WeakType) : WeakType := wt.
-
-Fixpoint weakTypeToCoreType' (wt:WeakType) : CoreType :=
+Fixpoint weakTypeToCoreType (wt:WeakType) : CoreType :=
match wt with
| WTyVarTy (weakTypeVar v _) => TyVarTy v
- | WAppTy t1 t2 => match (weakTypeToCoreType' t1) with
- | TyConApp tc tys => TyConApp tc (app tys ((weakTypeToCoreType' t2)::nil))
- | t1' => AppTy t1' (weakTypeToCoreType' t2)
+ | WAppTy (WAppTy WFunTyCon t1) t2 => FunTy (weakTypeToCoreType t1) (weakTypeToCoreType t2)
+ | WAppTy t1 t2 => match (weakTypeToCoreType t1) with
+ | TyConApp tc tys => TyConApp tc (app tys ((weakTypeToCoreType t2)::nil))
+ | t1' => AppTy t1' (weakTypeToCoreType t2)
end
| WTyCon tc => TyConApp tc nil
- | WTyFunApp tf lt => TyConApp tf (map weakTypeToCoreType' lt)
- | WClassP c lt => PredTy (ClassP c (map weakTypeToCoreType' lt))
- | WIParam n ty => PredTy (IParam n (weakTypeToCoreType' ty))
- | WForAllTy (weakTypeVar wtv _) t => ForAllTy wtv (weakTypeToCoreType' t)
+ | WTyFunApp tf lt => TyConApp tf (map weakTypeToCoreType lt)
+ | WClassP c lt => PredTy (ClassP c (map weakTypeToCoreType lt))
+ | WIParam n ty => PredTy (IParam n (weakTypeToCoreType ty))
+ | WForAllTy (weakTypeVar wtv _) t => ForAllTy wtv (weakTypeToCoreType t)
| WFunTyCon => TyConApp ArrowTyCon nil
- | WCodeTy (weakTypeVar ec _) t => TyConApp ModalBoxTyCon ((TyVarTy ec)::(weakTypeToCoreType' t)::nil)
- | WCoFunTy t1 t2 t3 => FunTy (PredTy (EqPred (weakTypeToCoreType' t1) (weakTypeToCoreType' t2)))
- (weakTypeToCoreType' t3)
+ | WCodeTy (weakTypeVar ec _) t => TyConApp ModalBoxTyCon ((TyVarTy ec)::(weakTypeToCoreType t)::nil)
+ | WCoFunTy t1 t2 t3 => FunTy (PredTy (EqPred (weakTypeToCoreType t1) (weakTypeToCoreType t2)))
+ (weakTypeToCoreType t3)
end.
-Definition weakTypeToCoreType (wt:WeakType) :=
- weakTypeToCoreType' (normalizeWeakType wt).
-
-Definition compare_weakTypes (w1 w2:WeakType) :=
- if coretype_eq_dec (weakTypeToCoreType w1) (weakTypeToCoreType w2)
- then true
- else false.
-
-(* Coq's "decide equality" can't cope here; we have to cheat for now *)
-Axiom compare_weakTypes_axiom : forall w1 w2, if compare_weakTypes w1 w2 then w1=w2 else not (w1=w2).
-
-Instance EqDecidableWeakType : EqDecidable WeakType.
- apply Build_EqDecidable.
- intros.
- set (compare_weakTypes_axiom v1 v2) as x.
- set (compare_weakTypes v1 v2) as y.
- assert (y=compare_weakTypes v1 v2). reflexivity.
- destruct y; rewrite <- H in x.
- left; auto.
- right; auto.
- Defined.
-
Instance WeakTypeToString : ToString WeakType :=
{ toString := coreTypeToString ○ weakTypeToCoreType }.
projects / coq-hetmet.git / blobdiff