From 1bdff05442f85e8618997d9e3f66cb774763a0a5 Mon Sep 17 00:00:00 2001
From: YoshiRulz <OSSYoshiRulz@gmail.com>
Date: Sun, 4 Dec 2022 04:25:58 +1000
Subject: [PATCH] Use read-only collection types in `IMemoryApi`

---
 src/BizHawk.Client.Common/Api/Classes/MemoryApi.cs   | 12 +++++-------
 .../Api/Interfaces/IMemoryApi.cs                     |  6 +++---
 .../lua/CommonLibs/MemoryLuaLibrary.cs               |  3 ++-
 3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/BizHawk.Client.Common/Api/Classes/MemoryApi.cs b/src/BizHawk.Client.Common/Api/Classes/MemoryApi.cs
index d110655b18..1014e2ff37 100644
--- a/src/BizHawk.Client.Common/Api/Classes/MemoryApi.cs
+++ b/src/BizHawk.Client.Common/Api/Classes/MemoryApi.cs
@@ -185,10 +185,8 @@ namespace BizHawk.Client.Common
 
 		public void SetBigEndian(bool enabled = true) => _isBigEndian = enabled;
 
-		public List<string> GetMemoryDomainList() =>
-			DomainList
-				.Select(domain => domain.Name)
-				.ToList();
+		public IReadOnlyCollection<string> GetMemoryDomainList()
+			=> DomainList.Select(static domain => domain.Name).ToList();
 
 		public uint GetMemoryDomainSize(string name = null) => (uint) NamedDomainOrCurrent(name).Size;
 
@@ -243,7 +241,7 @@ namespace BizHawk.Client.Common
 
 		public void WriteByte(long addr, uint value, string domain = null) => WriteUnsigned(addr, value, 1, domain);
 
-		public List<byte> ReadByteRange(long addr, int length, string domain = null)
+		public IReadOnlyList<byte> ReadByteRange(long addr, int length, string domain = null)
 		{
 			var d = NamedDomainOrCurrent(domain);
 			if (addr < 0) LogCallback($"Warning: Attempted reads on addresses {addr}..-1 outside range of domain {d.Name} in {nameof(ReadByteRange)}()");
@@ -255,10 +253,10 @@ namespace BizHawk.Client.Common
 				for (var i = addr < 0 ? -addr : 0; i != indexAfterLast; i++) bytes[i] = d.PeekByte(addr + i);
 			}
 			if (lastReqAddr >= d.Size) LogCallback($"Warning: Attempted reads on addresses {d.Size}..{lastReqAddr} outside range of domain {d.Name} in {nameof(ReadByteRange)}()");
-			return bytes.ToList();
+			return bytes;
 		}
 
-		public void WriteByteRange(long addr, List<byte> memoryblock, string domain = null)
+		public void WriteByteRange(long addr, IReadOnlyList<byte> memoryblock, string domain = null)
 		{
 			var d = NamedDomainOrCurrent(domain);
 			if (!d.Writable)
diff --git a/src/BizHawk.Client.Common/Api/Interfaces/IMemoryApi.cs b/src/BizHawk.Client.Common/Api/Interfaces/IMemoryApi.cs
index 09c49c53a3..52134d3cf4 100644
--- a/src/BizHawk.Client.Common/Api/Interfaces/IMemoryApi.cs
+++ b/src/BizHawk.Client.Common/Api/Interfaces/IMemoryApi.cs
@@ -8,7 +8,7 @@ namespace BizHawk.Client.Common
 
 		void SetBigEndian(bool enabled = true);
 
-		List<string> GetMemoryDomainList();
+		IReadOnlyCollection<string> GetMemoryDomainList();
 		uint GetMemoryDomainSize(string name = "");
 		string GetCurrentMemoryDomain();
 		uint GetCurrentMemoryDomainSize();
@@ -16,7 +16,7 @@ namespace BizHawk.Client.Common
 		string HashRegion(long addr, int count, string domain = null);
 
 		uint ReadByte(long addr, string domain = null);
-		List<byte> ReadByteRange(long addr, int length, string domain = null);
+		IReadOnlyList<byte> ReadByteRange(long addr, int length, string domain = null);
 		float ReadFloat(long addr, string domain = null);
 
 		int ReadS8(long addr, string domain = null);
@@ -30,7 +30,7 @@ namespace BizHawk.Client.Common
 		uint ReadU32(long addr, string domain = null);
 
 		void WriteByte(long addr, uint value, string domain = null);
-		void WriteByteRange(long addr, List<byte> memoryblock, string domain = null);
+		void WriteByteRange(long addr, IReadOnlyList<byte> memoryblock, string domain = null);
 		void WriteFloat(long addr, double value, string domain = null);
 
 		void WriteS8(long addr, int value, string domain = null);
diff --git a/src/BizHawk.Client.Common/lua/CommonLibs/MemoryLuaLibrary.cs b/src/BizHawk.Client.Common/lua/CommonLibs/MemoryLuaLibrary.cs
index 019be8a5e6..9faa385b26 100644
--- a/src/BizHawk.Client.Common/lua/CommonLibs/MemoryLuaLibrary.cs
+++ b/src/BizHawk.Client.Common/lua/CommonLibs/MemoryLuaLibrary.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
 
@@ -19,7 +20,7 @@ namespace BizHawk.Client.Common
 		[LuaMethod("getmemorydomainlist", "Returns a string of the memory domains for the loaded platform core. List will be a single string delimited by line feeds")]
 		[return: LuaASCIIStringParam]
 		public LuaTable GetMemoryDomainList()
-			=> _th.ListToTable(APIs.Memory.GetMemoryDomainList(), indexFrom: 0);
+			=> _th.ListToTable((List<string>) APIs.Memory.GetMemoryDomainList(), indexFrom: 0); //HACK cast will succeed as long as impl. returns .Select<T, string>().ToList() as IROC<string>
 
 		[LuaMethodExample("local uimemget = memory.getmemorydomainsize( mainmemory.getname( ) );")]
 		[LuaMethod("getmemorydomainsize", "Returns the number of bytes of the specified memory domain. If no domain is specified, or the specified domain doesn't exist, returns the current domain size")]