From aa0bee9f69822b4b781c300e35458d25f2c8a884 Mon Sep 17 00:00:00 2001
From: Quaternions <krakow20@gmail.com>
Date: Fri, 20 Sep 2024 13:51:17 -0700
Subject: [PATCH] the "transmute lifetimes" solution

---
 src/context.rs         |  7 ++++---
 src/runner/instance.rs |  3 ++-
 src/runner/runner.rs   | 25 +++++++++++--------------
 3 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/src/context.rs b/src/context.rs
index cc5f4e0..4ca6f66 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -10,16 +10,17 @@ pub fn class_is_a(class:&str,superclass:&str)->bool{
 	)
 }
 
+#[repr(transparent)]
 pub struct Context{
 	pub(crate)dom:WeakDom,
 }
 
 impl Context{
-	pub fn new(dom:WeakDom)->Context{
+	pub const fn new(dom:WeakDom)->Context{
 		Context{dom}
 	}
-	pub fn into_inner(self)->WeakDom{
-		self.dom
+	pub fn from_mut(dom:&mut WeakDom)->&mut Context{
+		unsafe{&mut *(dom as *mut WeakDom as *mut Context)}
 	}
 	/// Creates an iterator over all items of a particular class.
 	pub fn superclass_iter<'a>(&'a self,superclass:&'a str)->impl Iterator<Item=Ref>+'a{
diff --git a/src/runner/instance.rs b/src/runner/instance.rs
index 5ef7b6a..1289826 100644
--- a/src/runner/instance.rs
+++ b/src/runner/instance.rs
@@ -26,7 +26,8 @@ impl Instance{
 
 // LMAO look at this function!
 fn dom<T>(lua:&mlua::Lua,mut f:impl FnMut(&mut WeakDom)->mlua::Result<T>)->mlua::Result<T>{
-	f(&mut *lua.app_data_mut::<WeakDom>().ok_or(mlua::Error::runtime("DataModel missing"))?)
+	let mut dom=lua.app_data_mut::<&'static mut WeakDom>().ok_or(mlua::Error::runtime("DataModel missing"))?;
+	f(&mut *dom)
 }
 
 fn coerce_float(value:&mlua::Value)->Option<f32>{
diff --git a/src/runner/runner.rs b/src/runner/runner.rs
index 0d68d5e..fc0fbb6 100644
--- a/src/runner/runner.rs
+++ b/src/runner/runner.rs
@@ -76,19 +76,16 @@ impl Runner{
 		init(&runner.lua)?;
 		Ok(runner)
 	}
-	pub fn run_script(&self,script:crate::script::Script,context:Context)->(Context,Result<(),Error>){
-		let yoink=script.name_source(&context);
-		self.lua.set_app_data(context.dom);
-		let r=(||{
-			let (name,source)=yoink.map_err(Error::Script)?;
-				self.lua.globals().set("script",super::instance::Instance::from(script)).map_err(Error::Lua)?;
-			self.lua.load(source)
-			.set_name(name)
-			.exec().map_err(Error::Lua)?;
-			Ok(())
-		})();
-		let dom=self.lua.remove_app_data()
-			.expect("Fatal: Lua lost the dom");
-		(Context::new(dom),r)
+	pub fn run_script(&self,script:crate::script::Script,context:&mut Context)->Result<(),Error>{
+		let yoink=script.name_source(context);
+		//this makes set_app_data shut up about the lifetime
+		self.lua.set_app_data::<&'static mut rbx_dom_weak::WeakDom>(unsafe{core::mem::transmute(&mut context.dom)});
+		let (name,source)=yoink.map_err(Error::Script)?;
+			self.lua.globals().set("script",super::instance::Instance::from(script)).map_err(Error::Lua)?;
+		self.lua.load(source)
+		.set_name(name)
+		.exec().map_err(Error::Lua)?;
+		self.lua.remove_app_data::<&'static mut rbx_dom_weak::WeakDom>();
+		Ok(())
 	}
 }