From e1e8c9879af0afc3159ac429c4bafb117faef9ee Mon Sep 17 00:00:00 2001
From: Chris Anders <filmee24@gmail.com>
Date: Wed, 6 Nov 2024 18:16:44 +0100
Subject: [PATCH] feat: Add Operator Overloading Helpers

---
 .../Silverfly.Backend/OperatorOverloading.cs  | 57 +++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 Source/Silverfly.Backend/OperatorOverloading.cs

diff --git a/Source/Silverfly.Backend/OperatorOverloading.cs b/Source/Silverfly.Backend/OperatorOverloading.cs
new file mode 100644
index 0000000..d5cac47
--- /dev/null
+++ b/Source/Silverfly.Backend/OperatorOverloading.cs
@@ -0,0 +1,57 @@
+using System.Collections.Generic;
+using System.Linq;
+using DistIL.AsmIO;
+
+namespace Silverfly.Backend;
+
+public static class OperatorOverloading
+{
+    public static readonly Dictionary<string, string> BinMap = new()
+    {
+        ["+"] = "op_Addition",
+        ["/"] = "op_Division",
+        ["-"] = "op_Subtraction",
+        ["*"] = "op_Multiply",
+        ["%"] = "op_Modulus",
+
+        ["&"] = "op_BitwiseAnd",
+        ["|"] = "op_BitwiseOr",
+        ["^"] = "op_ExclusiveOr",
+        ["=="] = "op_Equality",
+        ["!="] = "op_Inequality",
+    };
+
+    public static readonly Dictionary<string, string> UnMap = new()
+    {
+        ["!"] = "op_LogicalNot",
+        ["-"] = "op_UnaryNegation",
+        ["~"] = "op_OnesComplement",
+
+        ["implicit"] = "op_Implicit",
+        ["explicit"] = "op_Explicit",
+    };
+
+    public static bool TryGetOperator(this TypeDesc type, string op, out MethodDesc opMethod, params TypeDesc[] args)
+    {
+        var nameMap = args.Length switch
+        {
+            1 => UnMap,
+            2 => BinMap,
+            _ => null
+        };
+
+        if (nameMap!.TryGetValue(op, out var opMethodName))
+        {
+            var candidate = type.FindMethod(opMethodName, new MethodSig(new TypeSig(), args.Select(type=> new TypeSig(type)).ToList(), false), throwIfNotFound: false);
+
+            if (candidate != null)
+            {
+                opMethod = candidate;
+                return true;
+            }
+        }
+
+        opMethod = null;
+        return false;
+    }
+}