Misc printing improvement.

Author: Drup

lib/common/Type.ml

@@ -577,7 +577,7 @@ let rec pp ppf = function
   | Var var -> Fmt.pf ppf "'%a" Variable.pp var
   | FrozenVar var -> Fmt.pf ppf "^%a" Variable.pp var
   | Constr (lid, [||]) -> LongIdent.pp ppf lid
-  | Constr (lid, params) -> Fmt.pf ppf "%a@ %a" pp_array params LongIdent.pp lid
+  | Constr (lid, params) -> Fmt.pf ppf "@[%a@ %a@]" pp_array params LongIdent.pp lid
   | Arrow (params, ret) ->
       Fmt.pf ppf "@[<2>(%a@ ->@ %a)@]" (NSet.pp pp_parens) params pp_parens ret
   | Tuple elts -> Fmt.pf ppf "@[<2>%a@]" (NSet.pp pp_parens) elts