Much more core internalization (Phase 3)

src/Microsoft.ML.Core/CommandLine/CmdLexer.cs

@@ -302,7 +302,8 @@ public static string UnquoteValue(string str)
         }
     }
 
-    public sealed class CmdQuoter
+    [BestFriend]
+    internal sealed class CmdQuoter
     {
         private readonly string _str;
         private StringBuilder _sb;

src/Microsoft.ML.Core/CommandLine/CmdParser.cs

@@ -537,16 +537,10 @@ private static ArgumentInfo GetArgumentInfo(Type type, object defaults)
 
         private static ArgumentAttribute GetAttribute(FieldInfo field)
         {
-            var attrs = field.GetCustomAttributes(typeof(ArgumentAttribute), false).ToArray();
-            if (attrs.Length == 1)
-            {
-                var argumentAttribute = (ArgumentAttribute)attrs[0];
-                if (argumentAttribute.Visibility == ArgumentAttribute.VisibilityType.EntryPointsOnly)
-                    return null;
-                return argumentAttribute;
-            }
-            Contracts.Assert(attrs.Length == 0);
-            return null;
+            var argumentAttribute = field.GetCustomAttribute<ArgumentAttribute>(false);
+            if (argumentAttribute?.Visibility == ArgumentAttribute.VisibilityType.EntryPointsOnly)
+                return null;
+            return argumentAttribute;
         }
 
         private void ReportUnrecognizedArgument(string argument)

src/Microsoft.ML.Core/ComponentModel/ComponentCatalog.cs

@@ -40,7 +40,8 @@ internal ComponentCatalog()
         /// <summary>
         /// Provides information on an instantiatable component, aka, loadable class.
         /// </summary>
-        public sealed class LoadableClassInfo
+        [BestFriend]
+        internal sealed class LoadableClassInfo
         {
             /// <summary>
             /// Used for dictionary lookup based on signature and name.
@@ -264,7 +265,8 @@ public object CreateArguments()
         /// <summary>
         /// A description of a single entry point.
         /// </summary>
-        public sealed class EntryPointInfo
+        [BestFriend]
+        internal sealed class EntryPointInfo
         {
             public readonly string Name;
             public readonly string Description;
@@ -333,7 +335,8 @@ private Type[] FindEntryPointKinds(Type type)
         /// The 'component' is a non-standalone building block that is used to parametrize entry points or other ML.NET components.
         /// For example, 'Loss function', or 'similarity calculator' could be components.
         /// </summary>
-        public sealed class ComponentInfo
+        [BestFriend]
+        internal sealed class ComponentInfo
         {
             public readonly string Name;
             public readonly string Description;
@@ -616,7 +619,8 @@ public void RegisterAssembly(Assembly assembly, bool throwOnError = true)
         /// Return an array containing information for all instantiatable components.
         /// If provided, the given set of assemblies is loaded first.
         /// </summary>
-        public LoadableClassInfo[] GetAllClasses()
+        [BestFriend]
+        internal LoadableClassInfo[] GetAllClasses()
         {
             return _classes.ToArray();
         }
@@ -625,7 +629,8 @@ public LoadableClassInfo[] GetAllClasses()
         /// Return an array containing information for instantiatable components with the given
         /// signature and base type. If provided, the given set of assemblies is loaded first.
         /// </summary>
-        public LoadableClassInfo[] GetAllDerivedClasses(Type typeBase, Type typeSig)
+        [BestFriend]
+        internal LoadableClassInfo[] GetAllDerivedClasses(Type typeBase, Type typeSig)
         {
             Contracts.CheckValue(typeBase, nameof(typeBase));
             Contracts.CheckValueOrNull(typeSig);
@@ -643,15 +648,17 @@ public LoadableClassInfo[] GetAllDerivedClasses(Type typeBase, Type typeSig)
         /// Return an array containing all the known signature types. If provided, the given set of assemblies
         /// is loaded first.
         /// </summary>
-        public Type[] GetAllSignatureTypes()
+        [BestFriend]
+        internal Type[] GetAllSignatureTypes()
         {
             return _signatures.Select(kvp => kvp.Key).ToArray();
         }
 
         /// <summary>
         /// Returns a string name for a given signature type.
         /// </summary>
-        public static string SignatureToString(Type sig)
+        [BestFriend]
+        internal static string SignatureToString(Type sig)
         {
             Contracts.CheckValue(sig, nameof(sig));
             Contracts.CheckParam(sig.BaseType == typeof(MulticastDelegate), nameof(sig), "Must be a delegate type");
@@ -670,7 +677,8 @@ private LoadableClassInfo FindClassCore(LoadableClassInfo.Key key)
             return null;
         }
 
-        public LoadableClassInfo[] FindLoadableClasses(string name)
+        [BestFriend]
+        internal LoadableClassInfo[] FindLoadableClasses(string name)
         {
             name = name.ToLowerInvariant().Trim();
 
@@ -680,14 +688,16 @@ public LoadableClassInfo[] FindLoadableClasses(string name)
             return res;
         }
 
-        public LoadableClassInfo[] FindLoadableClasses<TSig>()
+        [BestFriend]
+        internal LoadableClassInfo[] FindLoadableClasses<TSig>()
         {
             return _classes
                 .Where(ci => ci.SignatureTypes.Contains(typeof(TSig)))
                 .ToArray();
         }
 
-        public LoadableClassInfo[] FindLoadableClasses<TArgs, TSig>()
+        [BestFriend]
+        internal LoadableClassInfo[] FindLoadableClasses<TArgs, TSig>()
         {
             // REVIEW: this and above methods perform a linear search over all the loadable classes.
             // On 6/15/2015, TLC release build contained 431 of them, so adding extra lookups looks unnecessary at this time.
@@ -696,12 +706,14 @@ public LoadableClassInfo[] FindLoadableClasses<TArgs, TSig>()
                 .ToArray();
         }
 
-        public LoadableClassInfo GetLoadableClassInfo<TSig>(string loadName)
+        [BestFriend]
+        internal LoadableClassInfo GetLoadableClassInfo<TSig>(string loadName)
         {
             return GetLoadableClassInfo(loadName, typeof(TSig));
         }
 
-        public LoadableClassInfo GetLoadableClassInfo(string loadName, Type signatureType)
+        [BestFriend]
+        internal LoadableClassInfo GetLoadableClassInfo(string loadName, Type signatureType)
         {
             Contracts.CheckParam(signatureType.BaseType == typeof(MulticastDelegate), nameof(signatureType), "signatureType must be a delegate type");
             Contracts.CheckValueOrNull(loadName);
@@ -712,18 +724,21 @@ public LoadableClassInfo GetLoadableClassInfo(string loadName, Type signatureTyp
         /// <summary>
         /// Get all registered entry points.
         /// </summary>
-        public IEnumerable<EntryPointInfo> AllEntryPoints()
+        [BestFriend]
+        internal IEnumerable<EntryPointInfo> AllEntryPoints()
         {
             return _entryPoints.AsEnumerable();
         }
 
-        public bool TryFindEntryPoint(string name, out EntryPointInfo entryPoint)
+        [BestFriend]
+        internal bool TryFindEntryPoint(string name, out EntryPointInfo entryPoint)
         {
             Contracts.CheckNonEmpty(name, nameof(name));
             return _entryPointMap.TryGetValue(name, out entryPoint);
         }
 
-        public bool TryFindComponent(string kind, string alias, out ComponentInfo component)
+        [BestFriend]
+        internal bool TryFindComponent(string kind, string alias, out ComponentInfo component)
         {
             Contracts.CheckNonEmpty(kind, nameof(kind));
             Contracts.CheckNonEmpty(alias, nameof(alias));
@@ -733,15 +748,17 @@ public bool TryFindComponent(string kind, string alias, out ComponentInfo compon
             return _componentMap.TryGetValue($"{kind}:{alias}", out component);
         }
 
-        public bool TryFindComponent(Type argumentType, out ComponentInfo component)
+        [BestFriend]
+        internal bool TryFindComponent(Type argumentType, out ComponentInfo component)
         {
             Contracts.CheckValue(argumentType, nameof(argumentType));
 
             component = _components.FirstOrDefault(x => x.ArgumentType == argumentType);
             return component != null;
         }
 
-        public bool TryFindComponent(Type interfaceType, Type argumentType, out ComponentInfo component)
+        [BestFriend]
+        internal bool TryFindComponent(Type interfaceType, Type argumentType, out ComponentInfo component)
         {
             Contracts.CheckValue(interfaceType, nameof(interfaceType));
             Contracts.CheckParam(interfaceType.IsInterface, nameof(interfaceType), "Must be interface");
@@ -751,7 +768,8 @@ public bool TryFindComponent(Type interfaceType, Type argumentType, out Componen
             return component != null;
         }
 
-        public bool TryFindComponent(Type interfaceType, string alias, out ComponentInfo component)
+        [BestFriend]
+        internal bool TryFindComponent(Type interfaceType, string alias, out ComponentInfo component)
         {
             Contracts.CheckValue(interfaceType, nameof(interfaceType));
             Contracts.CheckParam(interfaceType.IsInterface, nameof(interfaceType), "Must be interface");
@@ -764,7 +782,8 @@ public bool TryFindComponent(Type interfaceType, string alias, out ComponentInfo
         /// Akin to <see cref="TryFindComponent(Type, string, out ComponentInfo)"/>, except if the regular (case sensitive) comparison fails, it will
         /// attempt to back off to a case-insensitive comparison.
         /// </summary>
-        public bool TryFindComponentCaseInsensitive(Type interfaceType, string alias, out ComponentInfo component)
+        [BestFriend]
+        internal bool TryFindComponentCaseInsensitive(Type interfaceType, string alias, out ComponentInfo component)
         {
             Contracts.CheckValue(interfaceType, nameof(interfaceType));
             Contracts.CheckParam(interfaceType.IsInterface, nameof(interfaceType), "Must be interface");
@@ -786,15 +805,17 @@ private static bool AnyMatch(string name, string[] aliases)
         /// <summary>
         /// Returns all valid component kinds.
         /// </summary>
-        public IEnumerable<string> GetAllComponentKinds()
+        [BestFriend]
+        internal IEnumerable<string> GetAllComponentKinds()
         {
             return _components.Select(x => x.Kind).Distinct().OrderBy(x => x);
         }
 
         /// <summary>
         /// Returns all components of the specified kind.
         /// </summary>
-        public IEnumerable<ComponentInfo> GetAllComponents(string kind)
+        [BestFriend]
+        internal IEnumerable<ComponentInfo> GetAllComponents(string kind)
         {
             Contracts.CheckNonEmpty(kind, nameof(kind));
             Contracts.CheckParam(IsValidName(kind), nameof(kind), "Invalid component kind");
@@ -804,13 +825,15 @@ public IEnumerable<ComponentInfo> GetAllComponents(string kind)
         /// <summary>
         /// Returns all components that implement the specified interface.
         /// </summary>
-        public IEnumerable<ComponentInfo> GetAllComponents(Type interfaceType)
+        [BestFriend]
+        internal IEnumerable<ComponentInfo> GetAllComponents(Type interfaceType)
         {
             Contracts.CheckValue(interfaceType, nameof(interfaceType));
             return _components.Where(x => x.InterfaceType == interfaceType).OrderBy(x => x.Name);
         }
 
-        public bool TryGetComponentKind(Type signatureType, out string kind)
+        [BestFriend]
+        internal bool TryGetComponentKind(Type signatureType, out string kind)
         {
             Contracts.CheckValue(signatureType, nameof(signatureType));
             // REVIEW: replace with a dictionary lookup.
@@ -821,7 +844,8 @@ public bool TryGetComponentKind(Type signatureType, out string kind)
             return faceAttr != null;
         }
 
-        public bool TryGetComponentShortName(Type type, out string name)
+        [BestFriend]
+        internal bool TryGetComponentShortName(Type type, out string name)
         {
             ComponentInfo component;
             if (!TryFindComponent(type, out component))
@@ -850,7 +874,8 @@ private static bool IsValidName(string name)
         /// <summary>
         /// Create an instance of the indicated component with the given extra parameters.
         /// </summary>
-        public static TRes CreateInstance<TRes>(IHostEnvironment env, Type signatureType, string name, string options, params object[] extra)
+        [BestFriend]
+        internal static TRes CreateInstance<TRes>(IHostEnvironment env, Type signatureType, string name, string options, params object[] extra)
             where TRes : class
         {
             TRes result;
@@ -863,13 +888,15 @@ public static TRes CreateInstance<TRes>(IHostEnvironment env, Type signatureType
         /// Try to create an instance of the indicated component and settings with the given extra parameters.
         /// If there is no such component in the catalog, returns false. Any other error results in an exception.
         /// </summary>
-        public static bool TryCreateInstance<TRes, TSig>(IHostEnvironment env, out TRes result, string name, string options, params object[] extra)
+        [BestFriend]
+        internal static bool TryCreateInstance<TRes, TSig>(IHostEnvironment env, out TRes result, string name, string options, params object[] extra)
             where TRes : class
         {
             return TryCreateInstance<TRes>(env, typeof(TSig), out result, name, options, extra);
         }
 
-        private static bool TryCreateInstance<TRes>(IHostEnvironment env, Type signatureType, out TRes result, string name, string options, params object[] extra)
+        [BestFriend]
+        internal static bool TryCreateInstance<TRes>(IHostEnvironment env, Type signatureType, out TRes result, string name, string options, params object[] extra)
             where TRes : class
         {
             Contracts.CheckValue(env, nameof(env));

src/Microsoft.ML.Core/ComponentModel/ComponentFactory.cs

@@ -48,7 +48,8 @@ public interface IComponentFactory<in TArg1, in TArg2, in TArg3, out TComponent>
     /// <summary>
     /// A utility class for creating <see cref="IComponentFactory"/> instances.
     /// </summary>
-    public static class ComponentFactoryUtils
+    [BestFriend]
+    internal static class ComponentFactoryUtils
     {
         /// <summary>
         /// Creates a component factory with no extra parameters (other than an <see cref="IHostEnvironment"/>)

src/Microsoft.ML.Core/ComponentModel/LoadableClassAttribute.cs

@@ -12,10 +12,12 @@ namespace Microsoft.ML.Runtime
     /// <summary>
     /// Common signature type with no extra parameters.
     /// </summary>
-    public delegate void SignatureDefault();
+    [BestFriend]
+    internal delegate void SignatureDefault();
 
     [AttributeUsage(AttributeTargets.Assembly, AllowMultiple = true)]
-    public sealed class LoadableClassAttribute : LoadableClassAttributeBase
+    [BestFriend]
+    internal sealed class LoadableClassAttribute : LoadableClassAttributeBase
     {
         /// <summary>
         /// Assembly attribute used to specify that a class is loadable by a machine learning
@@ -98,7 +100,7 @@ public LoadableClassAttribute(string summary, Type instType, Type loaderType, Ty
         }
     }
 
-    public abstract class LoadableClassAttributeBase : Attribute
+    internal abstract class LoadableClassAttributeBase : Attribute
     {
         // Note: these properties have private setters to make attribute parsing easier - the values
         // are all guaranteed to be in the ConstructorArguments of the CustomAttributeData

src/Microsoft.ML.Core/Data/DataKind.cs

@@ -52,7 +52,8 @@ public enum DataKind : byte
     /// <summary>
     /// Extension methods related to the DataKind enum.
     /// </summary>
-    public static class DataKindExtensions
+    [BestFriend]
+    internal static class DataKindExtensions
     {
         public const DataKind KindMin = DataKind.I1;
         public const DataKind KindLim = DataKind.U16 + 1;

src/Microsoft.ML.Core/Data/IHostEnvironment.cs

@@ -233,7 +233,8 @@ public interface IChannel : IPipe<ChannelMessage>
     /// that do not belong in more specific areas, for example, <see cref="Contracts"/> or
     /// component creation.
     /// </summary>
-    public static class HostExtensions
+    [BestFriend]
+    internal static class HostExtensions
     {
         public static T Apply<T>(this IHost host, string channelName, Func<IChannel, T> func)
         {

src/Microsoft.ML.Core/Data/IValueMapper.cs

@@ -9,13 +9,15 @@ namespace Microsoft.ML.Runtime.Data
     /// <summary>
     /// Delegate type to map/convert a value.
     /// </summary>
-    public delegate void ValueMapper<TSrc, TDst>(in TSrc src, ref TDst dst);
+    [BestFriend]
+    internal delegate void ValueMapper<TSrc, TDst>(in TSrc src, ref TDst dst);
 
     /// <summary>
     /// Delegate type to map/convert among three values, for example, one input with two
     /// outputs, or two inputs with one output.
     /// </summary>
-    public delegate void ValueMapper<TVal1, TVal2, TVal3>(in TVal1 val1, ref TVal2 val2, ref TVal3 val3);
+    [BestFriend]
+    internal delegate void ValueMapper<TVal1, TVal2, TVal3>(in TVal1 val1, ref TVal2 val2, ref TVal3 val3);
 
     /// <summary>
     /// Interface for mapping a single input value (of an indicated ColumnType) to

src/Microsoft.ML.Core/Data/RoleMappedSchema.cs

@@ -469,7 +469,8 @@ public RoleMappedSchema(Schema schema, string label, string feature,
     /// Note that the schema of <see cref="RoleMappedSchema.Schema"/> of <see cref="Schema"/> is
     /// guaranteed to equal the the <see cref="IDataView.Schema"/> of <see cref="Data"/>.
     /// </summary>
-    public sealed class RoleMappedData
+    [BestFriend]
+    internal sealed class RoleMappedData
     {
         /// <summary>
         /// The data.