Convert Type fields to use graph.Type

Add text encoding methods to replace string storage.

graph/iterator_test.go

@@ -0,0 +1,45 @@
+// Copyright 2014 The Cayley Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package graph
+
+import (
+	"testing"
+)
+
+func TestTypeEncodingRoundtrip(t *testing.T) {
+	for i := Invalid; i <= Materialize; i++ {
+		text, err := i.MarshalText()
+		if err != nil {
+			t.Errorf("Unexpected error when marshaling %s: %v", i, err)
+		}
+		if string(text) != i.String() {
+			t.Errorf("Unexpected MarshalText result, got:%q expect:%q", i, text)
+		}
+		var m Type
+		err = m.UnmarshalText(text)
+		if i == Invalid {
+			if err == nil || err.Error() != `graph: unknown iterator label: "invalid"` {
+				t.Errorf("Unexpected error when unmarshaling %q: %v", text, err)
+			}
+		} else {
+			if err != nil {
+				t.Errorf("Unexpected error when unmarshaling %q: %v", text, err)
+			}
+		}
+		if m != i {
+			t.Errorf("Unexpected UnmarshalText result, got:Type(%d) expect:Type(%d)", m, i)
+		}
+	}
+}