X-Git-Url: http://nitlanguage.org?ds=sidebyside

diff --git a/src/naive_interpreter.nit b/src/naive_interpreter.nit
index 0682043..4818e57 100644
--- a/src/naive_interpreter.nit
+++ b/src/naive_interpreter.nit
@@ -341,9 +341,11 @@ private class NaiveInterpreter
 		var mproperty = mpropdef.mproperty
 		if self.modelbuilder.mpropdef2npropdef.has_key(mpropdef) then
 			var npropdef = self.modelbuilder.mpropdef2npropdef[mpropdef]
+			self.parameter_check(npropdef, mpropdef, args)
 			return npropdef.call(self, mpropdef, args)
 		else if mproperty.name == "init" then
 			var nclassdef = self.modelbuilder.mclassdef2nclassdef[mpropdef.mclassdef]
+			self.parameter_check(nclassdef, mpropdef, args)
 			return nclassdef.call(self, mpropdef, args)
 		else
 			fatal("Fatal Error: method {mpropdef} not found in the AST")
@@ -351,6 +353,28 @@ private class NaiveInterpreter
 		end
 	end
 
+	# Generate type checks in the C code to check covariant parameters
+	fun parameter_check(node: ANode, mpropdef: MMethodDef, args: Array[Instance])
+	do
+		var msignature = mpropdef.msignature
+		for i in [0..msignature.arity[ do
+			# skip test for vararg since the array is instantiated with the correct polymorphic type
+			if msignature.vararg_rank == i then continue
+
+			# skip if the cast is not required
+			var origmtype =  mpropdef.mproperty.intro.msignature.mparameters[i].mtype
+			if not origmtype.need_anchor then continue
+
+			# get the parameter type
+			var mtype = msignature.mparameters[i].mtype
+			var anchor = args.first.mtype.as(MClassType)
+			mtype = mtype.anchor_to(self.mainmodule, anchor)
+			if not args[i+1].mtype.is_subtype(self.mainmodule, anchor, mtype) then
+				node.fatal(self, "Cast failed")
+			end
+		end
+	end
+
 	fun call_closure(closure: ClosureInstance, args: Array[Instance]): nullable Instance
 	do
 		var nclosuredef = closure.nclosuredef
@@ -391,16 +415,7 @@ private class NaiveInterpreter
 			fatal("Reciever is null")
 			abort
 		end
-		var propdefs = mproperty.lookup_definitions(self.mainmodule, mtype)
-		if propdefs.length > 1 then
-			fatal("NOT YET IMPLEMETED ERROR: Property conflict: {propdefs.join(", ")}")
-			abort
-		end
-		assert propdefs.length == 1 else
-			fatal("Fatal Error: No property '{mproperty}' for '{recv}'")
-			abort
-		end
-		var propdef = propdefs.first
+		var propdef = mproperty.lookup_first_definition(self.mainmodule, mtype)
 		return self.call(propdef, args)
 	end
 
@@ -662,11 +677,11 @@ redef class AInternMethPropdef
 			end
 		else if pname == "output_class_name" then
 			var recv = args.first
-			print recv.mtype.as(MClassType).mclass
+			print recv.mtype
 			return null
 		else if pname == "native_class_name" then
 			var recv = args.first
-			var txt = recv.mtype.as(MClassType).mclass.to_s
+			var txt = recv.mtype.to_s
 			return v.native_string_instance(txt)
 		else if pname == "==" then
 			# == is correclt redefined for instances
@@ -1578,6 +1593,7 @@ redef class AAttrExpr
 	do
 		var recv = v.expr(self.n_expr)
 		if recv == null then return null
+		if recv.mtype isa MNullType then fatal(v, "Reciever is null")
 		var mproperty = self.mproperty.as(not null)
 		return v.read_attribute(mproperty, recv)
 	end
@@ -1588,6 +1604,7 @@ redef class AAttrAssignExpr
 	do
 		var recv = v.expr(self.n_expr)
 		if recv == null then return
+		if recv.mtype isa MNullType then fatal(v, "Reciever is null")
 		var i = v.expr(self.n_value)
 		if i == null then return
 		var mproperty = self.mproperty.as(not null)
@@ -1601,6 +1618,7 @@ redef class AAttrReassignExpr
 	do
 		var recv = v.expr(self.n_expr)
 		if recv == null then return
+		if recv.mtype isa MNullType then fatal(v, "Reciever is null")
 		var value = v.expr(self.n_value)
 		if value == null then return
 		var mproperty = self.mproperty.as(not null)
@@ -1617,6 +1635,7 @@ redef class AIssetAttrExpr
 	do
 		var recv = v.expr(self.n_expr)
 		if recv == null then return null
+		if recv.mtype isa MNullType then fatal(v, "Reciever is null")
 		var mproperty = self.mproperty.as(not null)
 		assert recv isa MutableInstance
 		return v.bool_instance(recv.attributes.has_key(mproperty))