Implement new transition.

Assets/Cryville/Crtr/JsonPdtExpConverter.cs

@@ -0,0 +1,19 @@
+using Cryville.Common.Pdt;
+using Newtonsoft.Json;
+using System;
+
+namespace Cryville.Crtr {
+	public class JsonPdtExpConverter : JsonConverter<PdtExpression> {
+		static readonly PdtFragmentInterpreter _itor = new PdtFragmentInterpreter();
+		public override PdtExpression ReadJson(JsonReader reader, Type objectType, PdtExpression existingValue, bool hasExistingValue, JsonSerializer serializer) {
+			_itor.SetSource((string)reader.Value);
+			return _itor.GetExp();
+		}
+
+		public override void WriteJson(JsonWriter writer, PdtExpression value, JsonSerializer serializer) {
+			throw new NotSupportedException();
+		}
+
+		public override bool CanWrite { get { return false; } }
+	}
+}