Override ToString on more UIX classes

UIX/Microsoft/Iris/Markup/EventSchema.cs

@@ -10,8 +10,8 @@ namespace Microsoft.Iris.Markup
 {
     public abstract class EventSchema : DisposableObject
     {
-        private TypeSchema _owner;
-        public static EventSchema[] EmptyList = new EventSchema[0];
+        private readonly TypeSchema _owner;
+        public readonly static EventSchema[] EmptyList = System.Array.Empty<EventSchema>();
 
         public EventSchema(TypeSchema owner)
         {
@@ -22,5 +22,7 @@ namespace Microsoft.Iris.Markup
         public TypeSchema Owner => _owner;
 
         public abstract string Name { get; }
+
+        public override string ToString() => $"{_owner.Name}.{Name}";
     }
 }

UIX/Microsoft/Iris/Markup/PropertySchema.cs

@@ -10,8 +10,8 @@ namespace Microsoft.Iris.Markup
 {
     public abstract class PropertySchema : DisposableObject
     {
-        public static PropertySchema[] EmptyList = new PropertySchema[0];
-        private TypeSchema _owner;
+        public readonly static PropertySchema[] EmptyList = System.Array.Empty<PropertySchema>();
+        private readonly TypeSchema _owner;
 
         public PropertySchema(TypeSchema owner)
         {
@@ -44,5 +44,7 @@ namespace Microsoft.Iris.Markup
         public abstract object GetValue(object instance);
 
         public abstract void SetValue(ref object instance, object value);
+
+        public override string ToString() => $"{Owner.Name}.{Name}";
     }
 }

UIX/Microsoft/Iris/Markup/SymbolRecord.cs

@@ -11,6 +11,8 @@ namespace Microsoft.Iris.Markup
         public string Name;
         public TypeSchema Type;
         public SymbolOrigin SymbolOrigin;
-        public static SymbolRecord[] EmptyList = new SymbolRecord[0];
+        public readonly static SymbolRecord[] EmptyList = System.Array.Empty<SymbolRecord>();
+
+        public override string ToString() => $"{Type} {Name}";
     }
 }

UIX/Microsoft/Iris/Markup/SymbolReference.cs

@@ -20,5 +20,7 @@ namespace Microsoft.Iris.Markup
         public string Symbol => _symbol;
 
         public SymbolOrigin Origin => _origin;
+
+        public override string ToString() => Symbol;
     }
 }

UIX/Microsoft/Iris/Markup/TypeSchema.cs

@@ -12,12 +12,12 @@ namespace Microsoft.Iris.Markup
 {
     public abstract class TypeSchema : DisposableObject
     {
-        private LoadResult _owner;
-        private ulong _id;
+        private readonly LoadResult _owner;
+        private readonly ulong _id;
         private Vector<TypeSchema> _equivalents;
         private static ulong s_uniqueId;
-        private static Map<ulong, TypeSchema> s_idToTypeSchema = new Map<ulong, TypeSchema>();
-        public static TypeSchema[] EmptyList = new TypeSchema[0];
+        private readonly static Map<ulong, TypeSchema> s_idToTypeSchema = new();
+        public readonly static TypeSchema[] EmptyList = Array.Empty<TypeSchema>();
 
         public TypeSchema(LoadResult owner)
         {
@@ -232,7 +232,7 @@ namespace Microsoft.Iris.Markup
 
         public void ShareEquivalents(Vector<TypeSchema> equivalents) => _equivalents = equivalents;
 
-        public virtual string ErrorContextDescription => string.Format("{0} (Owner='{1}')", Name, Owner.Uri ?? "Unavailable");
+        public virtual string ErrorContextDescription => $"{Name} (Owner='{Owner.Uri ?? "Unavailable"}')";
 
         public static string NameFromInstance(object instance) => !(instance is ISchemaInfo schemaInfo) ? instance.GetType().Name : schemaInfo.TypeSchema.Name;
 
@@ -244,5 +244,7 @@ namespace Microsoft.Iris.Markup
             s_idToTypeSchema.TryGetValue(id, out typeSchema);
             return typeSchema;
         }
+
+        public override string ToString() => $"typeof({Name})";
     }
 }

UIX/Microsoft/Iris/Markup/UIXTypeSchema.cs

@@ -11,10 +11,10 @@ namespace Microsoft.Iris.Markup
 {
     internal class UIXTypeSchema : TypeSchema
     {
-        private short _typeID;
-        private short _baseTypeID;
-        private string _name;
-        private string _alternateName;
+        private readonly short _typeID;
+        private readonly short _baseTypeID;
+        private readonly string _name;
+        private readonly string _alternateName;
         private TypeSchema _baseType;
         private DefaultConstructHandler _defaultConstructor;
         private ConstructorSchema[] _constructors;
@@ -28,9 +28,9 @@ namespace Microsoft.Iris.Markup
         private PerformOperationHandler _performOperation;
         private SupportsOperationHandler _supportsOperation;
         private FindCanonicalInstanceHandler _findCanonicalInstance;
-        private Type _instanceType;
-        private UIXTypeFlags _flags;
-        private static object[] EmptyParameterList = new object[0];
+        private readonly Type _instanceType;
+        private readonly UIXTypeFlags _flags;
+        private static readonly object[] EmptyParameterList = Array.Empty<object>();
 
         public UIXTypeSchema(
           short typeID,