Detect cycles in type declarations

[tiger.ml.git] / compiler / src / lib / tiger / tiger_error.mli

diff --git a/compiler/src/lib/tiger/tiger_error.mli b/compiler/src/lib/tiger/tiger_error.mli
index 9090ad4..73505b8 100644 (file)
--- a/compiler/src/lib/tiger/tiger_error.mli
+++ b/compiler/src/lib/tiger/tiger_error.mli
@@ -4,6 +4,12 @@ module Sym = Tiger_symbol
 module Typ = Tiger_env_type
 
 type t =
+  | Cycle_in_type_decs of
+      { from_id  : Sym.t
+      ; from_pos : Pos.t
+      ;   to_id  : Sym.t
+      ;   to_pos : Pos.t
+      }
   | Invalid_syntax    of Pos.t
   | Unknown_id        of {id    : Sym.t; pos : Pos.t}
   | Unknown_type      of {ty_id : Sym.t; pos : Pos.t}
@@ -78,3 +84,4 @@ val is_invalid_syntax : t -> bool
 val is_not_a_record : t -> bool
 val is_not_an_array : t -> bool
 val is_no_such_field_in_record : t -> bool
+val is_cycle_in_type_dec : t -> bool