Even better handling of embedded objects

MatFileHandler.Tests/MatFileReaderTests.cs

@@ -388,6 +388,30 @@ namespace MatFileHandler.Tests
             Assert.Equal(new[] { 1.0, 3.0, 5.0, 2.0, 4.0, 6.0 }, variable2.ConvertToDoubleArray());
         }
 
+        /// <summary>
+        /// Test reading a deeply nested table.
+        /// </summary>
+        [Theory, MemberData(nameof(TestDataFactories))]
+        public void TestDeepTable(AbstractTestDataFactory<IMatFile> testFactory)
+        {
+            var matFile = testFactory["table-deep"];
+            var obj = matFile["t"].Value as IMatObject;
+            var table = new TableAdapter(obj);
+            Assert.Equal(1, table.NumberOfRows);
+            Assert.Equal(2, table.NumberOfVariables);
+            Assert.Equal(new[] { "s", "another" }, table.VariableNames);
+            var s = table["s"] as IStructureArray;
+            Assert.Equal(new[] { "a", "b", "c" }, s.FieldNames);
+            var c = s["c", 0];
+            var internalTable = new TableAdapter(c);
+            Assert.Equal(2, internalTable.NumberOfRows);
+            Assert.Equal(2, internalTable.NumberOfVariables);
+            Assert.Equal(new[] { "x", "y" }, internalTable.VariableNames);
+            var y = new StringAdapter(internalTable["y"]);
+            Assert.Equal("3", y[0]);
+            Assert.Equal("abc", y[1]);
+        }
+
         /// <summary>
         /// Test reading a table with strings
         /// </summary>

MatFileHandler/ObjectParser.cs

@@ -0,0 +1,30 @@
+// Copyright 2017-2018 Alexander Luzgarev
+
+namespace MatFileHandler
+{
+    /// <summary>
+    /// Parser for object data.
+    /// </summary>
+    internal static class ObjectParser
+    {
+        /// <summary>
+        /// Parse object data.
+        /// </summary>
+        /// <param name="uintArray">Opaque link array.</param>
+        /// <param name="subsystemData">Current subsystem data.</param>
+        /// <returns>Parsed object.</returns>
+        public static IArray ParseObject(MatNumericalArrayOf<uint> uintArray, SubsystemData subsystemData)
+        {
+            var (dimensions, indexToObjectId, classIndex) = DataElementReader.ParseOpaqueData(uintArray.Data);
+            return new OpaqueLink(
+                uintArray.Name,
+                string.Empty,
+                string.Empty,
+                dimensions,
+                uintArray,
+                indexToObjectId,
+                classIndex,
+                subsystemData);
+        }
+    }
+}

MatFileHandler/SubsystemDataReader.cs

@@ -317,21 +317,11 @@ namespace MatFileHandler
 
         private static IArray TransformOpaqueData(IArray array, SubsystemData subsystemData)
         {
-            if (array is MatNumericalArrayOf<uint> uintArray)
+            if (array is MatNumericalArrayOf<uint> uintArray &&
+                uintArray.Data.Length == 6 &&
+                uintArray.Data[0] == 3707764736u)
             {
-                if (uintArray.Data[0] == 3707764736u)
+                return ObjectParser.ParseObject(uintArray, subsystemData);
-                {
-                    var (dimensions, indexToObjectId, classIndex) = DataElementReader.ParseOpaqueData(uintArray.Data);
-                    return new OpaqueLink(
-                        uintArray.Name,
-                        string.Empty,
-                        string.Empty,
-                        dimensions,
-                        uintArray,
-                        indexToObjectId,
-                        classIndex,
-                        subsystemData);
-                }
             }
 
             if (array is MatCellArray cellArray)
@@ -344,6 +334,26 @@ namespace MatFileHandler
                 }
             }
 
+            if (array is MatStructureArray structureArray)
+            {
+                var newFields = new Dictionary<string, List<IArray>>();
+                foreach (var pair in structureArray.Fields)
+                {
+                    var values = pair.Value;
+                    var transformedValues = new List<IArray>(values.Count);
+                    foreach (var value in values)
+                    {
+                        var transformedValue = TransformOpaqueData(value, subsystemData);
+                        transformedValues.Add(transformedValue);
+                    }
+                    newFields[pair.Key] = transformedValues;
+                }
+                foreach (var pair in newFields)
+                {
+                    structureArray.Fields[pair.Key] = pair.Value;
+                }
+            }
+
             return array;
         }