make scheduler into a crate feature

Cargo.toml

@@ -7,6 +7,10 @@ license = "MIT OR Apache-2.0"
 description = "Run embedded Luau scripts which manipulate the DOM."
 authors = ["Rhys Lloyd <krakow20@gmail.com>"]
 
+[features]
+default=["run-service"]
+run-service=[]
+
 [dependencies]
 glam = "0.29.0"
 mlua = { version = "0.10.0-beta", features = ["luau"] }

src/lib.rs

@@ -1,5 +1,7 @@
 pub mod runner;
 pub mod context;
+#[cfg(feature="run-service")]
+pub(crate) mod scheduler;
 
 #[cfg(test)]
 mod tests;

src/runner/runner.rs

@@ -1,4 +1,6 @@
 use crate::context::Context;
+#[cfg(feature="run-service")]
+use crate::scheduler::scheduler_mut;
 
 pub struct Runner{
 	lua:mlua::Lua,
@@ -29,6 +31,8 @@ fn init(lua:&mlua::Lua)->mlua::Result<()>{
 	//global environment
 	let globals=lua.globals();
 
+	#[cfg(feature="run-service")]
+	crate::scheduler::set_globals(lua,&globals)?;
 	super::r#enum::set_globals(lua,&globals)?;
 	super::color3::set_globals(lua,&globals)?;
 	super::vector3::set_globals(lua,&globals)?;
@@ -60,6 +64,8 @@ impl Runner{
 		}
 		//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)});
+		#[cfg(feature="run-service")]
+		self.lua.set_app_data::<crate::scheduler::Scheduler>(crate::scheduler::Scheduler::default());
 		Ok(Runnable{
 			lua:self.lua,
 			_lifetime:&std::marker::PhantomData
@@ -75,15 +81,43 @@ pub struct Runnable<'a>{
 impl Runnable<'_>{
 	pub fn drop_context(self)->Runner{
 		self.lua.remove_app_data::<&'static mut rbx_dom_weak::WeakDom>();
+		#[cfg(feature="run-service")]
+		self.lua.remove_app_data::<crate::scheduler::Scheduler>();
 		Runner{
 			lua:self.lua,
 		}
 	}
 	pub fn run_script(&self,script:super::instance::Instance)->Result<(),Error>{
 		let (name,source)=super::instance::get_name_source(&self.lua,script).map_err(Error::RustLua)?;
-		self.lua.globals().set("script",script).map_err(Error::RustLua)?;
+		self.lua.globals().raw_set("script",script).map_err(Error::RustLua)?;
-		self.lua.load(source.as_str())
+		let f=self.lua.load(source.as_str())
-		.set_name(name)
+		.set_name(name).into_function().map_err(Error::RustLua)?;
-		.exec().map_err(|error|Error::Lua{source,error})
+		// TODO: set_environment without losing the ability to print from Lua
+		let thread=self.lua.create_thread(f).map_err(Error::RustLua)?;
+		thread.resume::<mlua::MultiValue>(()).map_err(|error|Error::Lua{source,error})?;
+		// wait() is called from inside Lua and goes to a rust function that schedules the thread and then yields
+		// No need to schedule the thread here
+		Ok(())
+	}
+	#[cfg(feature="run-service")]
+	pub fn has_scheduled_threads(&self)->Result<bool,mlua::Error>{
+		scheduler_mut(&self.lua,|scheduler|
+			Ok(scheduler.has_scheduled_threads())
+		)
+	}
+	#[cfg(feature="run-service")]
+	pub fn game_tick(&self)->Result<(),mlua::Error>{
+		if let Some(threads)=scheduler_mut(&self.lua,|scheduler|Ok(scheduler.tick_threads()))?{
+			for thread in threads{
+				//TODO: return dt and total run time
+				let result=thread.resume::<mlua::MultiValue>((1.0/30.0,0.0))
+					.map_err(|error|Error::Lua{source:"source unavailable".to_owned(),error});
+				match result{
+					Ok(_)=>(),
+					Err(e)=>println!("game_tick Error: {e}"),
+				}
+			}
+		}
+		Ok(())
 	}
 }

src/scheduler.rs

@@ -0,0 +1,99 @@
+pub use tick::Tick;
+mod tick{
+	#[derive(Clone,Copy,Default,Hash,PartialEq,Eq,PartialOrd,Ord)]
+	pub struct Tick(u64);
+	impl Tick{
+		pub const fn new(value:u64)->Self{
+			Self(value)
+		}
+		pub const fn get(&self)->u64{
+			self.0
+		}
+	}
+	impl std::ops::Add<u64> for Tick{
+		type Output=Self;
+		fn add(self,rhs:u64)->Self::Output{
+			Self(self.0+rhs)
+		}
+	}
+	impl std::ops::Sub<u64> for Tick{
+		type Output=Self;
+		fn sub(self,rhs:u64)->Self::Output{
+			Self(self.0-rhs)
+		}
+	}
+	impl std::ops::AddAssign<u64> for Tick{
+		fn add_assign(&mut self,rhs:u64){
+			self.0+=rhs;
+		}
+	}
+	impl std::ops::SubAssign<u64> for Tick{
+		fn sub_assign(&mut self,rhs:u64){
+			self.0-=rhs;
+		}
+	}
+}
+#[derive(Default)]
+pub struct Scheduler{
+	tick:Tick,
+	schedule:std::collections::HashMap<Tick,Vec<mlua::Thread>>,
+}
+
+impl Scheduler{
+	pub const fn tick(&self)->Tick{
+		self.tick
+	}
+	pub fn has_scheduled_threads(&self)->bool{
+		!self.schedule.is_empty()
+	}
+	pub fn schedule_thread(&mut self,delay:u64,thread:mlua::Thread){
+		self.schedule.entry(self.tick+delay.max(1))
+		.or_insert(Vec::new())
+		.push(thread);
+	}
+	pub fn tick_threads(&mut self)->Option<Vec<mlua::Thread>>{
+		self.tick+=1;
+		self.schedule.remove(&self.tick)
+	}
+}
+
+fn coerce_float64(value:&mlua::Value)->Option<f64>{
+	match value{
+		&mlua::Value::Integer(i)=>Some(i as f64),
+		&mlua::Value::Number(f)=>Some(f),
+		_=>None,
+	}
+}
+pub fn scheduler_mut<T>(lua:&mlua::Lua,mut f:impl FnMut(&mut crate::scheduler::Scheduler)->mlua::Result<T>)->mlua::Result<T>{
+	let mut scheduler=lua.app_data_mut::<crate::scheduler::Scheduler>().ok_or(mlua::Error::runtime("Scheduler missing"))?;
+	f(&mut *scheduler)
+}
+pub fn set_globals(lua:&mlua::Lua,globals:&mlua::Table)->Result<(),mlua::Error>{
+	let schedule_thread=lua.create_function(move|lua,dt:mlua::Value|{
+		let delay=coerce_float64(&dt).ok_or(mlua::Error::runtime("Expected float"))?.max(0.0)*60.0;
+		if delay<u64::MAX as f64{
+			scheduler_mut(lua,|scheduler|{
+				scheduler.schedule_thread((delay as u64).max(2),lua.current_thread());
+				Ok(())
+			}).unwrap();
+		}
+		Ok(())
+	})?;
+	let wait_env=lua.create_table()?;
+	wait_env.raw_set("coroutine",globals.get::<mlua::Table>("coroutine")?)?;
+	wait_env.raw_set("schedule_thread",schedule_thread)?;
+	let wait=lua.load("
+		local coroutine_yield=coroutine.yield
+		local schedule_thread=schedule_thread
+		return function(dt)
+			schedule_thread(dt)
+			return coroutine_yield()
+		end
+	")
+	.set_name("wait")
+	.set_environment(wait_env)
+	.call::<mlua::Function>(())?;
+	globals.raw_set("wait",wait)?;
+
+	Ok(())
+}