print should use __str__ or __repr__ when available

Author: raff

builtin/builtin.go

@@ -189,6 +189,14 @@ func builtin_print(self py.Object, args py.Tuple, kwargs py.StringDict) (py.Obje
 	end := endObj.(py.String)
 	// FIXME ignoring file and flush
 	for i, v := range args {
+                switch sv := v.(type) {
+                    case py.I__str__:
+                        v, _ = sv.M__str__()
+
+                    case py.I__repr__:
+                        v, _ = sv.M__repr__()
+                }
+
 		fmt.Printf("%v", v)
 		if i != len(args)-1 {
 			fmt.Print(sep)