Merge: Fix type adaptation when there is loops

[nit.git] / src / semantize / typing.nit

diff --git a/src/semantize/typing.nit b/src/semantize/typing.nit
index ee93c2e..a46f632 100644 (file)
--- a/src/semantize/typing.nit
+++ b/src/semantize/typing.nit
@@ -239,12 +239,16 @@ private class TypeVisitor
 
                if not mtype2 isa MNullType then return
 
-               if mtype isa MNullType then return
-
                # Check of useless null
                if not check_can_be_null(anode.n_expr, mtype) then return
 
-               mtype = mtype.as_notnull
+               if mtype isa MNullType then
+                       # Because of type adaptation, we cannot just stop here
+                       # so return use `null` as a bottom type that will be merged easily (cf) `merge_types`
+                       mtype = null
+               else
+                       mtype = mtype.as_notnull
+               end
 
                # Check for type adaptation
                var variable = anode.n_expr.its_variable
@@ -1871,6 +1875,7 @@ redef class ANewExpr
                end
 
                self.recvtype = recvtype
+               var kind = recvtype.mclass.kind
 
                var name: String
                var nid = self.n_id
@@ -1879,11 +1884,24 @@ redef class ANewExpr
                else
                        name = "new"
                end
+               if name == "intern" then
+                       if kind != concrete_kind then
+                               v.error(self, "Type Error: Cannot instantiate {kind} {recvtype}.")
+                               return
+                       end
+                       if n_args.n_exprs.not_empty then
+                               v.error(n_args, "Type Error: the intern constructor expects no arguments.")
+                               return
+                       end
+                       # Our job is done
+                       self.mtype = recvtype
+                       return
+               end
+
                var callsite = v.get_method(self, recvtype, name, false)
                if callsite == null then return
 
                if not callsite.mproperty.is_new then
-                       var kind = recvtype.mclass.kind
                        if kind != concrete_kind then
                                v.error(self, "Type Error: Cannot instantiate {kind} {recvtype}.")
                                return