[abstracts] remove some underlying type checks in unify_with_variance

src/core/tUnification.ml

@@ -979,16 +979,15 @@ and unify_with_variance uctx f t1 t2 =
 	let t1 = follow t1 in
 	let t2 = follow t2 in
 	let unify_param t1 t2 = with_variance (get_nested_context uctx) f t1 t2 in
-	let get_after_abstract_context () = get_after_abstract_context uctx t1 t2 in
 	let rec get_underlying_type t = match follow t with
 		| TAbstract(a,tl) ->
 			let tl = List.map get_underlying_type tl in
 			let t = apply_params a.a_params tl a.a_this in
 			if Meta.has Meta.CoreType a.a_meta then t else get_underlying_type t
 		| t -> t
 	in
-	let compare_underlying equality_kind a b = type_eq {uctx with equality_kind = equality_kind} a b in
 	let unifies_abstract uctx t ab tl ats =
+		let uctx = get_after_abstract_context uctx t1 t2 in
 		List.exists (does_func_unify_arg (fun at ->
 			let at = apply_params ab.a_params tl at in
 			if ats == ab.a_to then
@@ -1006,16 +1005,11 @@ and unify_with_variance uctx f t1 t2 =
 	| TAbstract(a1,tl1),TAbstract(a2,tl2) when a1 == a2 ->
 		List.iter2 unify_param tl1 tl2
 	| TAbstract(a1,tl1),TAbstract(a2,tl2) ->
-		let uctx = get_after_abstract_context() in
-		compare_underlying EqStrict (get_underlying_type t1) (get_underlying_type t2);
 		if not (unifies_abstract uctx t2 a1 tl1 a1.a_to) && not (unifies_abstract uctx t1 a2 tl2 a2.a_from) then fail();
+		type_eq {uctx with equality_kind = EqStrict} (get_underlying_type t1) (get_underlying_type t2);
 	| TAbstract(a,tl),_ ->
-		let uctx = get_after_abstract_context() in
-		compare_underlying EqBothDynamic (get_underlying_type t1) t2;
-		if not (unifies_abstract uctx t2 a tl a.a_to) then fail();
+		if not (unifies_abstract uctx t2 a tl a.a_to) then fail()
 	| _,TAbstract(a,tl) ->
-		let uctx = get_after_abstract_context() in
-		compare_underlying EqBothDynamic t1 (get_underlying_type t2);
 		if not (unifies_abstract uctx t1 a tl a.a_from) then fail()
 	| TAnon(a1),TAnon(a2) ->
 		rec_stack_default unify_stack (t1,t2) (fast_eq_pair (t1,t2)) (fun() -> unify_anons uctx t1 t2 a1 a2) ()