diff options
| author | Jacques Garrigue <garrigue at math.nagoya-u.ac.jp> | 2002-02-01 02:49:48 +0000 |
|---|---|---|
| committer | Jacques Garrigue <garrigue at math.nagoya-u.ac.jp> | 2002-02-01 02:49:48 +0000 |
| commit | bfc6db3edc23be93bedb0893fb10b3fe894d85c1 (patch) | |
| tree | f8a58a5badeff1e7743cd67b8e3abcf071fd57d2 | |
| parent | 20f9b3e86b40a71c57fd9ab390ccbe250e8d9844 (diff) | |
PR#841
git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@4333 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
| -rw-r--r-- | typing/ctype.ml | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/typing/ctype.ml b/typing/ctype.ml index 693075d43..b43d5c260 100644 --- a/typing/ctype.ml +++ b/typing/ctype.ml @@ -1005,9 +1005,18 @@ let rec occur_rec env visited ty0 ty = | _ -> iter_type_expr (occur_rec env visited ty0) ty +let type_changed = ref false (* trace possible changes to the studied type *) + let occur env ty0 ty = - if not !Clflags.recursive_types then - try occur_rec env [] ty0 ty with Occur -> raise (Unify []) + if not !Clflags.recursive_types then + let old = !type_changed in + try + while type_changed := false; occur_rec env [] ty0 ty; !type_changed + do () (* prerr_endline "changed" *) done; + type_changed := old + with exn -> + type_changed := old; + raise (match exn with Occur -> Unify [] | _ -> exn) (*****************) @@ -1079,6 +1088,7 @@ let rec unify env t1 t2 = if t1 == t2 then () else try + type_changed := true; match (t1.desc, t2.desc) with (Tvar, Tconstr _) when deep_occur t1 t2 -> unify2 env t1 t2 |