From 8ec278035619cb66bfeb7ed653e9a89932002f59 Mon Sep 17 00:00:00 2001
From: cosmonaut <evan@moonside.games>
Date: Wed, 16 Mar 2022 00:33:38 -0700
Subject: [PATCH] add singular ReadMessage to System

---
 src/MessageDepot.cs   | 7 ++++++-
 src/MessageStorage.cs | 5 +++++
 src/System.cs         | 7 ++++++-
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/MessageDepot.cs b/src/MessageDepot.cs
index a5a66e9..ef91f6d 100644
--- a/src/MessageDepot.cs
+++ b/src/MessageDepot.cs
@@ -24,11 +24,16 @@ internal class MessageDepot
 		return Lookup<TMessage>().Some();
 	}
 
-	public ReadOnlySpan<TMessage> Read<TMessage>() where TMessage : struct
+	public ReadOnlySpan<TMessage> ReadAll<TMessage>() where TMessage : struct
 	{
 		return Lookup<TMessage>().All();
 	}
 
+	public TMessage ReadFirst<TMessage>() where TMessage : struct
+	{
+		return Lookup<TMessage>().First();
+	}
+
 	public void Clear()
 	{
 		foreach (var storage in storages.Values)
diff --git a/src/MessageStorage.cs b/src/MessageStorage.cs
index bf180cc..8bfe24f 100644
--- a/src/MessageStorage.cs
+++ b/src/MessageStorage.cs
@@ -38,6 +38,11 @@ internal class MessageStorage<TMessage> : MessageStorage where TMessage : struct
 		return new ReadOnlySpan<TMessage>(messages, 0, count);
 	}
 
+	public TMessage First()
+	{
+		return messages[0];
+	}
+
 	public override void Clear()
 	{
 		count = 0;
diff --git a/src/System.cs b/src/System.cs
index cc00c8e..1c166a1 100644
--- a/src/System.cs
+++ b/src/System.cs
@@ -38,7 +38,12 @@ public abstract class System : EntityComponentReader
 
 	protected ReadOnlySpan<TMessage> ReadMessages<TMessage>() where TMessage : struct
 	{
-		return MessageDepot.Read<TMessage>();
+		return MessageDepot.ReadAll<TMessage>();
+	}
+
+	protected TMessage ReadMessage<TMessage>() where TMessage : struct
+	{
+		return MessageDepot.ReadFirst<TMessage>();
 	}
 
 	protected bool SomeMessage<TMessage>() where TMessage : struct