Refactor `call_async()` functions to use static dispatch outside of traits

src/chunk.rs

@@ -11,9 +11,6 @@ use crate::lua::Lua;
 use crate::table::Table;
 use crate::value::{FromLuaMulti, IntoLua, IntoLuaMulti};
 
-#[cfg(feature = "async")]
-use futures_util::future::{self, LocalBoxFuture};
-
 /// Trait for types [loadable by Lua] and convertible to a [`Chunk`]
 ///
 /// [loadable by Lua]: https://www.lua.org/manual/5.4/manual.html#3.3.2
@@ -312,8 +309,8 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     /// [`exec`]: #method.exec
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn exec_async(self) -> LocalBoxFuture<'lua, Result<()>> {
-        self.call_async(())
+    pub async fn exec_async(self) -> Result<()> {
+        self.call_async(()).await
     }
 
     /// Evaluate the chunk as either an expression or block.
@@ -344,17 +341,16 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     /// [`eval`]: #method.eval
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn eval_async<'fut, R>(self) -> LocalBoxFuture<'fut, Result<R>>
+    pub async fn eval_async<R>(self) -> Result<R>
     where
-        'lua: 'fut,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         if self.detect_mode() == ChunkMode::Binary {
-            self.call_async(())
+            self.call_async(()).await
         } else if let Ok(function) = self.to_expression() {
-            function.call_async(())
+            function.call_async(()).await
         } else {
-            self.call_async(())
+            self.call_async(()).await
         }
     }
 
@@ -374,16 +370,12 @@ impl<'lua, 'a> Chunk<'lua, 'a> {
     /// [`call`]: #method.call
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn call_async<'fut, A, R>(self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    pub async fn call_async<A, R>(self, args: A) -> Result<R>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
-        match self.into_function() {
-            Ok(func) => func.call_async(args),
-            Err(e) => Box::pin(future::err(e)),
-        }
+        self.into_function()?.call_async(args).await
     }
 
     /// Load this chunk into a regular `Function`.

src/function.rs

@@ -17,7 +17,7 @@ use crate::value::{FromLuaMulti, IntoLua, IntoLuaMulti};
 #[cfg(feature = "async")]
 use {
     crate::types::AsyncCallback,
-    futures_util::future::{self, Future, LocalBoxFuture, TryFutureExt},
+    futures_util::future::{self, Future},
 };
 
 /// Handle to an internal Lua function.
@@ -77,7 +77,7 @@ pub struct FunctionInfo {
 #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct CoverageInfo {
-    pub function: Option<std::string::String>,
+    pub function: Option<String>,
     pub line_defined: i32,
     pub depth: i32,
     pub hits: Vec<i32>,
@@ -188,21 +188,18 @@ impl<'lua> Function<'lua> {
     /// [`AsyncThread`]: crate::AsyncThread
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    pub fn call_async<A, R>(&self, args: A) -> impl Future<Output = Result<R>> + 'lua
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         let lua = self.0.lua;
-        match lua.create_recycled_thread(self) {
-            Ok(t) => {
-                let mut t = t.into_async(args);
-                t.set_recyclable(true);
-                Box::pin(t)
-            }
-            Err(e) => Box::pin(future::err(e)),
-        }
+        let thread_res = lua.create_recycled_thread(self).map(|th| {
+            let mut th = th.into_async(args);
+            th.set_recyclable(true);
+            th
+        });
+        async move { thread_res?.await }
     }
 
     /// Returns a function that, when called, calls `self`, passing `args` as the first set of
@@ -544,12 +541,12 @@ impl OwnedFunction {
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
     #[inline]
-    pub fn call_async<'lua, A, R>(&'lua self, args: A) -> LocalBoxFuture<'lua, Result<R>>
+    pub async fn call_async<'lua, A, R>(&'lua self, args: A) -> Result<R>
     where
         A: IntoLuaMulti<'lua>,
         R: FromLuaMulti<'lua> + 'lua,
     {
-        self.to_ref().call_async(args)
+        self.to_ref().call_async(args).await
     }
 }
 
@@ -604,7 +601,8 @@ impl<'lua> Function<'lua> {
                 Ok(args) => args,
                 Err(e) => return Box::pin(future::err(e)),
             };
-            Box::pin(func(lua, args).and_then(move |ret| future::ready(ret.into_lua_multi(lua))))
+            let fut = func(lua, args);
+            Box::pin(async move { fut.await?.into_lua_multi(lua) })
         }))
     }
 }

src/lua.rs

@@ -58,7 +58,7 @@ use crate::{
 #[cfg(feature = "async")]
 use {
     crate::types::{AsyncCallback, AsyncCallbackUpvalue, AsyncPollUpvalue},
-    futures_util::future::{self, Future, TryFutureExt},
+    futures_util::future::{self, Future},
     futures_util::task::{noop_waker_ref, Context, Poll, Waker},
 };
 
@@ -1619,7 +1619,8 @@ impl Lua {
                 Ok(args) => args,
                 Err(e) => return Box::pin(future::err(e)),
             };
-            Box::pin(func(lua, args).and_then(move |ret| future::ready(ret.into_lua_multi(lua))))
+            let fut = func(lua, args);
+            Box::pin(async move { fut.await?.into_lua_multi(lua) })
         }))
     }
 

src/table.rs

@@ -888,11 +888,10 @@ pub trait TableExt<'lua>: Sealed {
     /// The metamethod is called with the table as its first argument, followed by the passed arguments.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 
     /// Gets the function associated to `key` from the table and executes it,
     /// passing the table itself along with `args` as function arguments.
@@ -928,12 +927,11 @@ pub trait TableExt<'lua>: Sealed {
     /// This might invoke the `__index` metamethod.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_method<'fut, K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async_method<K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         K: IntoLua<'lua>,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 
     /// Gets the function associated to `key` from the table and asynchronously executes it,
     /// passing `args` as function arguments and returning Future.
@@ -943,16 +941,11 @@ pub trait TableExt<'lua>: Sealed {
     /// This might invoke the `__index` metamethod.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_function<'fut, K, A, R>(
-        &self,
-        key: K,
-        args: A,
-    ) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async_function<K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         K: IntoLua<'lua>,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 }
 
 impl<'lua> TableExt<'lua> for Table<'lua> {
@@ -966,13 +959,17 @@ impl<'lua> TableExt<'lua> for Table<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
-        Function(self.0.clone()).call_async(args)
+        let args = match args.into_lua_multi(self.0.lua) {
+            Ok(args) => args,
+            Err(e) => return Box::pin(future::err(e)),
+        };
+        let func = Function(self.0.clone());
+        Box::pin(async move { func.call_async(args).await })
     }
 
     fn call_method<K, A, R>(&self, key: K, args: A) -> Result<R>
@@ -997,12 +994,11 @@ impl<'lua> TableExt<'lua> for Table<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async_method<'fut, K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async_method<K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         K: IntoLua<'lua>,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         let lua = self.0.lua;
         let mut args = match args.into_lua_multi(lua) {
@@ -1014,15 +1010,19 @@ impl<'lua> TableExt<'lua> for Table<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async_function<'fut, K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async_function<K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         K: IntoLua<'lua>,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
+        let lua = self.0.lua;
+        let args = match args.into_lua_multi(lua) {
+            Ok(args) => args,
+            Err(e) => return Box::pin(future::err(e)),
+        };
         match self.get::<_, Function>(key) {
-            Ok(func) => func.call_async(args),
+            Ok(func) => Box::pin(async move { func.call_async(args).await }),
             Err(e) => Box::pin(future::err(e)),
         }
     }

src/userdata_ext.rs

@@ -27,11 +27,10 @@ pub trait AnyUserDataExt<'lua>: Sealed {
     /// The metamethod is called with the userdata as its first argument, followed by the passed arguments.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 
     /// Calls the userdata method, assuming it has `__index` metamethod
     /// and a function associated to `name`.
@@ -48,15 +47,14 @@ pub trait AnyUserDataExt<'lua>: Sealed {
     /// This might invoke the `__index` metamethod.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_method<'fut, A, R>(
+    fn call_async_method<A, R>(
         &self,
         name: impl AsRef<str>,
         args: A,
-    ) -> LocalBoxFuture<'fut, Result<R>>
+    ) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 
     /// Gets the function associated to `key` from the table and executes it,
     /// passing `args` as function arguments.
@@ -78,15 +76,14 @@ pub trait AnyUserDataExt<'lua>: Sealed {
     /// This might invoke the `__index` metamethod.
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    fn call_async_function<'fut, A, R>(
+    fn call_async_function<A, R>(
         &self,
         name: impl AsRef<str>,
         args: A,
-    ) -> LocalBoxFuture<'fut, Result<R>>
+    ) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut;
+        R: FromLuaMulti<'lua> + 'lua;
 }
 
 impl<'lua> AnyUserDataExt<'lua> for AnyUserData<'lua> {
@@ -127,18 +124,24 @@ impl<'lua> AnyUserDataExt<'lua> for AnyUserData<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         let metatable = match self.get_metatable() {
             Ok(metatable) => metatable,
             Err(err) => return Box::pin(future::err(err)),
         };
         match metatable.get::<Value>(MetaMethod::Call) {
-            Ok(Value::Function(func)) => func.call_async((self.clone(), args)),
+            Ok(Value::Function(func)) => {
+                let mut args = match args.into_lua_multi(self.0.lua) {
+                    Ok(args) => args,
+                    Err(e) => return Box::pin(future::err(e)),
+                };
+                args.push_front(Value::UserData(self.clone()));
+                Box::pin(async move { func.call_async(args).await })
+            }
             Ok(_) => Box::pin(future::err(Error::RuntimeError(
                 "attempt to call a userdata value".to_string(),
             ))),
@@ -155,15 +158,14 @@ impl<'lua> AnyUserDataExt<'lua> for AnyUserData<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async_method<'fut, A, R>(
+    fn call_async_method<A, R>(
         &self,
         name: impl AsRef<str>,
         args: A,
-    ) -> LocalBoxFuture<'fut, Result<R>>
+    ) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         self.call_async_function(name, (self.clone(), args))
     }
@@ -183,22 +185,28 @@ impl<'lua> AnyUserDataExt<'lua> for AnyUserData<'lua> {
     }
 
     #[cfg(feature = "async")]
-    fn call_async_function<'fut, A, R>(
+    fn call_async_function<A, R>(
         &self,
         name: impl AsRef<str>,
         args: A,
-    ) -> LocalBoxFuture<'fut, Result<R>>
+    ) -> LocalBoxFuture<'lua, Result<R>>
     where
-        'lua: 'fut,
         A: IntoLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         match self.get(name.as_ref()) {
-            Ok(Value::Function(func)) => func.call_async(args),
-            Ok(val) => Box::pin(future::err(Error::RuntimeError(format!(
-                "attempt to call a {} value",
-                val.type_name()
-            )))),
+            Ok(Value::Function(func)) => {
+                let args = match args.into_lua_multi(self.0.lua) {
+                    Ok(args) => args,
+                    Err(e) => return Box::pin(future::err(e)),
+                };
+                Box::pin(async move { func.call_async(args).await })
+            }
+            Ok(val) => {
+                let type_name = val.type_name();
+                let msg = format!("attempt to call a {type_name} value");
+                Box::pin(future::err(Error::RuntimeError(msg)))
+            }
             Err(err) => Box::pin(future::err(err)),
         }
     }