Cleaned up TypeReaders

src/Discord.Net.Commands/CommandService.cs

@@ -2,7 +2,6 @@
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Collections.Immutable;
-using System.Globalization;
 using System.Linq;
 using System.Reflection;
 using System.Threading;
@@ -27,94 +26,56 @@ namespace Discord.Commands
             _map = new CommandMap();
             _typeReaders = new ConcurrentDictionary<Type, TypeReader>
             {
-                [typeof(string)] = new GenericTypeReader((m, s) => Task.FromResult(TypeReaderResult.FromSuccess(s))),
-                [typeof(byte)] = new GenericTypeReader((m, s) =>
-                {
-                    byte value;
-                    if (byte.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse Byte"));
-                }),
-                [typeof(sbyte)] = new GenericTypeReader((m, s) =>
-                {
-                    sbyte value;
-                    if (sbyte.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse SByte"));
-                }),
-                [typeof(ushort)] = new GenericTypeReader((m, s) =>
-                {
-                    ushort value;
-                    if (ushort.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse UInt16"));
-                }),
-                [typeof(short)] = new GenericTypeReader((m, s) =>
-                {
-                    short value;
-                    if (short.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse Int16"));
-                }),
-                [typeof(uint)] = new GenericTypeReader((m, s) =>
-                {
-                    uint value;
-                    if (uint.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse UInt32"));
-                }),
-                [typeof(int)] = new GenericTypeReader((m, s) =>
-                {
-                    int value;
-                    if (int.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse Int32"));
-                }),
-                [typeof(ulong)] = new GenericTypeReader((m, s) =>
-                {
-                    ulong value;
-                    if (ulong.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse UInt64"));
-                }),
-                [typeof(long)] = new GenericTypeReader((m, s) =>
-                {
-                    long value;
-                    if (long.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse Int64"));
-                }),
-                [typeof(float)] = new GenericTypeReader((m, s) =>
-                {
-                    float value;
-                    if (float.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse Single"));
-                }),
-                [typeof(double)] = new GenericTypeReader((m, s) =>
-                {
-                    double value;
-                    if (double.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse Double"));
-                }),
-                [typeof(decimal)] = new GenericTypeReader((m, s) =>
-                {
-                    decimal value;
-                    if (decimal.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse Decimal"));
-                }),
-                [typeof(DateTime)] = new GenericTypeReader((m, s) =>
-                {
-                    DateTime value;
-                    if (DateTime.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse DateTime"));
-                }),
-                [typeof(DateTimeOffset)] = new GenericTypeReader((m, s) =>
-                {
-                    DateTimeOffset value;
-                    if (DateTimeOffset.TryParse(s, out value)) return Task.FromResult(TypeReaderResult.FromSuccess(value));
-                    return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, "Failed to parse DateTimeOffset"));
-                }),
+                [typeof(string)] = new SimpleTypeReader<string>(),
+                [typeof(byte)] = new SimpleTypeReader<byte>(),
+                [typeof(sbyte)] = new SimpleTypeReader<sbyte>(),
+                [typeof(ushort)] = new SimpleTypeReader<ushort>(),
+                [typeof(short)] = new SimpleTypeReader<short>(),
+                [typeof(uint)] = new SimpleTypeReader<uint>(),
+                [typeof(int)] = new SimpleTypeReader<int>(),
+                [typeof(ulong)] = new SimpleTypeReader<ulong>(),
+                [typeof(long)] = new SimpleTypeReader<long>(),
+                [typeof(float)] = new SimpleTypeReader<float>(),
+                [typeof(double)] = new SimpleTypeReader<double>(),
+                [typeof(decimal)] = new SimpleTypeReader<decimal>(),
+                [typeof(DateTime)] = new SimpleTypeReader<DateTime>(),
+                [typeof(DateTimeOffset)] = new SimpleTypeReader<DateTimeOffset>(),
+
+                //TODO: Do we want to support any other interfaces?
+
+                //[typeof(IMentionable)] = new GeneralTypeReader(),
+                //[typeof(ISnowflakeEntity)] = new GeneralTypeReader(),
+                //[typeof(IEntity<ulong>)] = new GeneralTypeReader(),
 
                 [typeof(IMessage)] = new MessageTypeReader(),
+                //[typeof(IAttachment)] = new xxx(),
+                //[typeof(IEmbed)] = new xxx(),
+
                 [typeof(IChannel)] = new ChannelTypeReader<IChannel>(),
+                [typeof(IDMChannel)] = new ChannelTypeReader<IDMChannel>(),
+                [typeof(IGroupChannel)] = new ChannelTypeReader<IGroupChannel>(),
                 [typeof(IGuildChannel)] = new ChannelTypeReader<IGuildChannel>(),
+                [typeof(IMessageChannel)] = new ChannelTypeReader<IMessageChannel>(),
+                [typeof(IPrivateChannel)] = new ChannelTypeReader<IPrivateChannel>(),
                 [typeof(ITextChannel)] = new ChannelTypeReader<ITextChannel>(),
                 [typeof(IVoiceChannel)] = new ChannelTypeReader<IVoiceChannel>(),
+
+                //[typeof(IGuild)] = new GuildTypeReader<IGuild>(),
+                //[typeof(IUserGuild)] = new GuildTypeReader<IUserGuild>(),
+                //[typeof(IGuildIntegration)] = new xxx(),
+
                 [typeof(IRole)] = new RoleTypeReader(),
+
+                //[typeof(IInvite)] = new InviteTypeReader<IInvite>(),
+                //[typeof(IInviteMetadata)] = new InviteTypeReader<IInviteMetadata>(),
+
                 [typeof(IUser)] = new UserTypeReader<IUser>(),
-                [typeof(IGuildUser)] = new UserTypeReader<IGuildUser>()
+                [typeof(IGroupUser)] = new UserTypeReader<IGroupUser>(),
+                [typeof(IGuildUser)] = new UserTypeReader<IGuildUser>(),
+                //[typeof(ISelfUser)] = new UserTypeReader<ISelfUser>(),
+                //[typeof(IPresence)] = new UserTypeReader<IPresence>(),
+                //[typeof(IVoiceState)] = new UserTypeReader<IVoiceState>(),
+                //[typeof(IConnection)] = new xxx(),
             };
         }
 

src/Discord.Net.Commands/PrimitiveParsers.cs

@@ -0,0 +1,33 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+
+namespace Discord.Commands
+{
+    internal delegate bool TryParseDelegate<T>(string str, out T value);
+
+    internal static class PrimitiveParsers
+    {
+        private static readonly IReadOnlyDictionary<Type, Delegate> _parsers;
+
+        static PrimitiveParsers()
+        {
+            var parserBuilder = ImmutableDictionary.CreateBuilder<Type, Delegate>();
+            parserBuilder[typeof(string)] = (TryParseDelegate<string>)delegate(string str, out string value) { value = str; return true; };
+            parserBuilder[typeof(sbyte)] = (TryParseDelegate<sbyte>)sbyte.TryParse;
+            parserBuilder[typeof(byte)] = (TryParseDelegate<byte>)byte.TryParse;
+            parserBuilder[typeof(short)] = (TryParseDelegate<short>)short.TryParse;
+            parserBuilder[typeof(ushort)] = (TryParseDelegate<ushort>)ushort.TryParse;
+            parserBuilder[typeof(int)] = (TryParseDelegate<int>)int.TryParse;
+            parserBuilder[typeof(uint)] = (TryParseDelegate<uint>)uint.TryParse;
+            parserBuilder[typeof(long)] = (TryParseDelegate<long>)long.TryParse;
+            parserBuilder[typeof(ulong)] = (TryParseDelegate<ulong>)ulong.TryParse;
+            parserBuilder[typeof(DateTime)] = (TryParseDelegate<DateTime>)DateTime.TryParse;
+            parserBuilder[typeof(DateTimeOffset)] = (TryParseDelegate<DateTimeOffset>)DateTimeOffset.TryParse;
+            _parsers = parserBuilder.ToImmutable();
+        }
+
+        public static TryParseDelegate<T> Get<T>() => (TryParseDelegate<T>)_parsers[typeof(T)];
+        public static Delegate Get(Type type) => _parsers[type];
+    }
+}

src/Discord.Net.Commands/Readers/EnumTypeReader.cs

@@ -7,31 +7,13 @@ using System.Threading.Tasks;
 
 namespace Discord.Commands
 {
-    delegate bool TryParseDelegate<T>(string str, out T value);
-
     internal static class EnumTypeReader
-    {        
-        private static readonly IReadOnlyDictionary<Type, object> _parsers;
-
-        static EnumTypeReader()
-        {
-            var parserBuilder = ImmutableDictionary.CreateBuilder<Type, object>();
-            parserBuilder[typeof(sbyte)] = (TryParseDelegate<sbyte>)sbyte.TryParse;
-            parserBuilder[typeof(byte)] = (TryParseDelegate<byte>)byte.TryParse;
-            parserBuilder[typeof(short)] = (TryParseDelegate<short>)short.TryParse;
-            parserBuilder[typeof(ushort)] = (TryParseDelegate<ushort>)ushort.TryParse;
-            parserBuilder[typeof(int)] = (TryParseDelegate<int>)int.TryParse;
-            parserBuilder[typeof(uint)] = (TryParseDelegate<uint>)uint.TryParse;
-            parserBuilder[typeof(long)] = (TryParseDelegate<long>)long.TryParse;
-            parserBuilder[typeof(ulong)] = (TryParseDelegate<ulong>)ulong.TryParse;
-            _parsers = parserBuilder.ToImmutable();
-        }
-
+    {
         public static TypeReader GetReader(Type type)
         {
             Type baseType = Enum.GetUnderlyingType(type);
             var constructor = typeof(EnumTypeReader<>).MakeGenericType(baseType).GetTypeInfo().DeclaredConstructors.First();
-            return (TypeReader)constructor.Invoke(new object[] { type, _parsers[baseType] });
+            return (TypeReader)constructor.Invoke(new object[] { type, PrimitiveParsers.Get(baseType) });
         }
     }
 

src/Discord.Net.Commands/Readers/GenericTypeReader.cs

@@ -1,17 +0,0 @@
-using System;
-using System.Threading.Tasks;
-
-namespace Discord.Commands
-{
-    internal class GenericTypeReader : TypeReader
-    {
-        private readonly Func<IMessage, string, Task<TypeReaderResult>> _action;
-
-        public GenericTypeReader(Func<IMessage, string, Task<TypeReaderResult>> action)
-        {
-            _action = action;
-        }
-
-        public override Task<TypeReaderResult> Read(IMessage context, string input) => _action(context, input);
-    }
-}

src/Discord.Net.Commands/Readers/SimpleTypeReader.cs

@@ -0,0 +1,23 @@
+using System.Threading.Tasks;
+
+namespace Discord.Commands
+{
+    internal class SimpleTypeReader<T> : TypeReader
+    {
+        private readonly TryParseDelegate<T> _tryParse;
+
+        public SimpleTypeReader()
+        {
+            _tryParse = PrimitiveParsers.Get<T>();
+        }
+
+        public override Task<TypeReaderResult> Read(IMessage context, string input)
+        {
+            T value;
+            if (_tryParse(input, out value))
+                return Task.FromResult(TypeReaderResult.FromSuccess(value));
+            else
+                return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, $"Failed to parse {typeof(T).Name}"));
+        }
+    }
+}