Cleaned up TypeReaders

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];
+    }
+}