Fishery

2022-10-24 18:56:18 +02:00
parent 01ef055ff2
commit 9cdc8ccb4f
70 changed files with 19754 additions and 4 deletions
@@ -0,0 +1,122 @@
+// Copyright (c) 2022 bradson
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+using System.Linq;
+using System.Runtime.CompilerServices;
+
+namespace FisheryLib.FunctionPointers;
+public static class EqualsByRef<T>
+{
+	public static readonly unsafe delegate*<ref T, ref T, bool> Default = (delegate*<ref T, ref T, bool>)EqualsByRef.MakeDelegate(typeof(T));
+}
+
+public static class EqualsByRef
+{
+	public static class Methods
+	{
+		public static bool Byte(ref byte x, ref byte y)
+			=> x == y;
+
+		public static bool Int(ref int x, ref int y)
+			=> x == y;
+
+		public static bool Uint(ref uint x, ref uint y)
+			=> x == y;
+
+		public static bool Ushort(ref ushort x, ref ushort y)
+			=> x == y;
+
+		public static bool IntPtr(ref IntPtr x, ref IntPtr y)
+			=> x == y;
+
+		public static bool String(ref string x, ref string y)
+			=> string.Equals(x, y);
+
+		public static unsafe bool VoidPtr(ref void* x, ref void* y)
+			=> x == y;
+
+		public static bool RuntimeFieldHandle(ref RuntimeFieldHandle x, ref RuntimeFieldHandle y)
+			=> x.Value == y.Value;
+
+		public static bool RuntimeTypeHandle(ref RuntimeTypeHandle x, ref RuntimeTypeHandle y)
+			=> x.Value == y.Value;
+
+		public static bool RuntimeMethodHandle(ref RuntimeMethodHandle x, ref RuntimeMethodHandle y)
+			=> x.Value == y.Value;
+
+		public static bool Enum<T>(ref T x, ref T y) where T : struct
+			=> JitHelpers.UnsafeEnumCast(x) == JitHelpers.UnsafeEnumCast(y);
+
+		public static bool LongEnum<T>(ref T x, ref T y) where T : struct
+			=> JitHelpers.UnsafeEnumCastLong(x) == JitHelpers.UnsafeEnumCastLong(y);
+
+		public static bool EquatableValueType<T>(ref T x, ref T y) where T : struct, IEquatable<T>
+			=> x.Equals(y);
+
+		public static bool Nullable<T>(ref T? x, ref T? y) where T : struct, IEquatable<T>
+			=> x.HasValue
+			? y.HasValue && x.Value.Equals(y.Value)
+			: !y.HasValue;
+
+		public static bool EquatableReferenceType<T>(ref T x, ref T y) where T : IEquatable<T>
+			=> x != null
+			? y != null && x.Equals(y)
+			: y == null;
+
+		public static bool Reference<T>(ref T x, ref T y) where T : class
+			=> x == y;
+
+		public static bool Object<T>(ref T x, ref T y)
+			=> x != null
+			? y != null && x.Equals(y)
+			: y == null;
+	}
+
+	internal static unsafe IntPtr MakeDelegate(Type type)
+		=> _equalsMethods.Where(m => !m.IsGenericMethod)
+			.FirstOrDefault(m
+				=> m.GetParameters().First().ParameterType.GetElementType() == type)
+			is { } specializedMethod
+		? specializedMethod.GetFunctionPointer()
+		: type.IsAssignableTo(typeof(IEquatable<>), type)
+		? GetMethod(
+			type.IsValueType
+			? nameof(Methods.EquatableValueType)
+			: nameof(Methods.EquatableReferenceType))
+			.MakeGenericMethod(type)/*.CreateDelegate(typeof(EqualsDelegate<>).MakeGenericType(type)).Method*/.GetFunctionPointer()
+		: type.IsNullable(out var genericArgument)
+			&& genericArgument.IsAssignableTo(typeof(IEquatable<>), genericArgument)
+		? GetMethod(nameof(Methods.Nullable)).MakeGenericMethod(genericArgument)/*.CreateDelegate(typeof(EqualsDelegate<>).MakeGenericType(type)).Method*/.GetFunctionPointer()
+		: GetMethod(
+			type.IsEnum
+			? Type.GetTypeCode(Enum.GetUnderlyingType(type))
+				switch
+			{
+				TypeCode.Int16
+				or TypeCode.SByte
+				or TypeCode.Byte
+				or TypeCode.UInt16
+				or TypeCode.Int32
+				or TypeCode.UInt32 => nameof(Methods.Enum),
+				TypeCode.Int64
+				or TypeCode.UInt64 => nameof(Methods.LongEnum),
+				_ => ThrowHelper.ThrowNotSupportedException<string>()
+			}
+			: nameof(Methods.Object)
+		).MakeGenericMethod(type)/*.CreateDelegate(typeof(EqualsDelegate<>).MakeGenericType(type)).Method*/.GetFunctionPointer();
+
+	private static MethodInfo GetMethod(string name)
+		=> Array.Find(_equalsMethods, m => m.Name == name);
+
+	private static MethodInfo[] _equalsMethods
+		= typeof(Methods)
+		.GetMethods(BindingFlags.Static | BindingFlags.Public | BindingFlags.DeclaredOnly)
+		.Where(m
+			=> m.ReturnType == typeof(bool)
+			&& m.GetParameters().Length == 2)
+		.ToArray();
+
+	//internal delegate bool EqualsDelegate<T>(ref T x, ref T y);
+}