From 2057767e752b7f5d2012244210ae14d8ec2e051c Mon Sep 17 00:00:00 2001
From: Tjakka5 <justinvanderleij@gmail.com>
Date: Fri, 20 Dec 2019 19:00:47 +0100
Subject: [PATCH] Add world:hasSystem, world:getSystem

---
 src/world.lua | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/world.lua b/src/world.lua
index 217084e..50377d7 100644
--- a/src/world.lua
+++ b/src/world.lua
@@ -109,6 +109,22 @@ function World:flush()
    return self
 end
 
+function World:hasSystem(baseSystem)
+   if not Type.isBaseSystem(baseSystem) then
+      error("bad argument #1 to 'World:getSystem' (baseSystem expected, got "..type(baseSystem)..")", 2)
+   end
+
+   return self.__systemLookup[baseSystem] and true or false
+end
+
+function World:getSystem(baseSystem)
+   if not Type.isBaseSystem(baseSystem) then
+      error("bad argument #1 to 'World:getSystem' (baseSystem expected, got "..type(baseSystem)..")", 2)
+   end
+
+   return self.__systemLookup[baseSystem]
+end
+
 --- Adds a System to the World.
 -- @param baseSystem The BaseSystem of the system to add
 -- @param callbackName The callbackName to register to