add dyn for Fn (#2212)

* add dyn for Fn

* revert invalid-imports changes

* add one more dyn in doc comments

.gitignore

@@ -10,3 +10,4 @@ yarn.lock
 /publish
 /publish.exe
 .vscode
+webdriver.json

guide/src/contributing/design/describe.md

@@ -40,7 +40,7 @@ In addition to the shims we talked about above which JS generates the macro
 ```
 #[no_mangle]
 pub extern "C" fn __wbindgen_describe_greet() {
-    <Fn(&str)>::describe();
+    <dyn Fn(&str)>::describe();
 }
 ```
 

guide/src/contributing/design/rust-type-conversions.md

@@ -86,7 +86,7 @@ functions imported into Rust.
 Mentioned above not all Rust types will fit within 32 bits. While we can
 communicate an `f64` we don't necessarily have the ability to use all the bits.
 Types like `&str` need to communicate two items, a pointer and a length (64
-bits). Other types like `&Closure<Fn()>` have even more information to
+bits). Other types like `&Closure<dyn Fn()>` have even more information to
 transmit.
 
 As a result we need a method of communicating more data through the signatures

guide/src/reference/passing-rust-closures-to-js.md

@@ -11,17 +11,17 @@ JavaScript in two variants:
 
 ## Stack-Lifetime Closures
 
-Closures with a stack lifetime are passed to JavaScript as either `&Fn` or `&mut
-FnMut` trait objects:
+Closures with a stack lifetime are passed to JavaScript as either `&dyn Fn` or `&mut
+dyn FnMut` trait objects:
 
 ```rust
 // Import JS functions that take closures
 
 #[wasm_bindgen]
 extern "C" {
-    fn takes_immutable_closure(f: &Fn());
+    fn takes_immutable_closure(f: &dyn Fn());
 
-    fn takes_mutable_closure(f: &mut FnMut());
+    fn takes_mutable_closure(f: &mut dyn FnMut());
 }
 
 // Usage
@@ -45,7 +45,7 @@ Closures also support arguments and return values like exports do, for example:
 ```rust
 #[wasm_bindgen]
 extern "C" {
-    fn takes_closure_that_takes_int_and_returns_string(x: &Fn(u32) -> String);
+    fn takes_closure_that_takes_int_and_returns_string(x: &dyn Fn(u32) -> String);
 }
 
 takes_closure_that_takes_int_and_returns_string(&|x: u32| -> String {
@@ -81,7 +81,7 @@ as arguments and returns.
 ```rust
 #[wasm_bindgen]
 extern "C" {
-    fn setInterval(closure: &Closure<FnMut()>, millis: u32) -> f64;
+    fn setInterval(closure: &Closure<dyn FnMut()>, millis: u32) -> f64;
     fn cancelInterval(token: f64);
 
     #[wasm_bindgen(js_namespace = console)]
@@ -90,7 +90,7 @@ extern "C" {
 
 #[wasm_bindgen]
 pub struct Interval {
-    closure: Closure<FnMut()>,
+    closure: Closure<dyn FnMut()>,
     token: f64,
 }
 

guide/src/web-sys/type-translations.md

@@ -16,7 +16,7 @@ all Web APIs)][webidl] have relatively straightforward translations into
 * Callbacks are all represented as `js_sys::Function`. This means that all
   callbacks going through `web-sys` are a raw JS value. You can work with this
   by either juggling actual `js_sys::Function` instances or you can create a
-  `Closure<FnMut(...)>`, extract the underlying `JsValue` with `as_ref`, and
+  `Closure<dyn FnMut(...)>`, extract the underlying `JsValue` with `as_ref`, and
   then use `JsCast::unchecked_ref` to convert it to a `js_sys::Function`.
 
 [webidl]: https://heycam.github.io/webidl/

src/closure.rs

@@ -48,7 +48,7 @@ use crate::UnwrapThrowExt;
 ///
 /// #[wasm_bindgen]
 /// extern "C" {
-///     fn setInterval(closure: &Closure<FnMut()>, time: u32) -> i32;
+///     fn setInterval(closure: &Closure<dyn FnMut()>, time: u32) -> i32;
 ///     fn clearInterval(id: i32);
 ///
 ///     #[wasm_bindgen(js_namespace = console)]
@@ -58,7 +58,7 @@ use crate::UnwrapThrowExt;
 /// #[wasm_bindgen]
 /// pub struct IntervalHandle {
 ///     interval_id: i32,
-///     _closure: Closure<FnMut()>,
+///     _closure: Closure<dyn FnMut()>,
 /// }
 ///
 /// impl Drop for IntervalHandle {
@@ -73,7 +73,7 @@ use crate::UnwrapThrowExt;
 ///     // a JS closure.
 ///     let cb = Closure::wrap(Box::new(|| {
 ///         log("interval elapsed!");
-///     }) as Box<FnMut()>);
+///     }) as Box<dyn FnMut()>);
 ///
 ///     // Next we pass this via reference to the `setInterval` function, and
 ///     // `setInterval` gets a handle to the corresponding JS closure.
@@ -101,7 +101,7 @@ use crate::UnwrapThrowExt;
 /// #[wasm_bindgen]
 /// pub struct IntervalHandle {
 ///     interval_id: i32,
-///     _closure: Closure<FnMut()>,
+///     _closure: Closure<dyn FnMut()>,
 /// }
 ///
 /// impl Drop for IntervalHandle {
@@ -115,7 +115,7 @@ use crate::UnwrapThrowExt;
 /// pub fn run() -> Result<IntervalHandle, JsValue> {
 ///     let cb = Closure::wrap(Box::new(|| {
 ///         web_sys::console::log_1(&"inverval elapsed!".into());
-///     }) as Box<FnMut()>);
+///     }) as Box<dyn FnMut()>);
 ///
 ///     let window = web_sys::window().unwrap();
 ///     let interval_id = window.set_interval_with_callback_and_timeout_and_arguments_0(
@@ -144,7 +144,7 @@ use crate::UnwrapThrowExt;
 ///
 /// #[wasm_bindgen]
 /// extern "C" {
-///     fn requestAnimationFrame(closure: &Closure<FnMut()>) -> u32;
+///     fn requestAnimationFrame(closure: &Closure<dyn FnMut()>) -> u32;
 ///     fn cancelAnimationFrame(id: u32);
 ///
 ///     #[wasm_bindgen(js_namespace = console)]
@@ -154,7 +154,7 @@ use crate::UnwrapThrowExt;
 /// #[wasm_bindgen]
 /// pub struct AnimationFrameHandle {
 ///     animation_id: u32,
-///     _closure: Closure<FnMut()>,
+///     _closure: Closure<dyn FnMut()>,
 /// }
 ///
 /// impl Drop for AnimationFrameHandle {
@@ -377,12 +377,12 @@ where
 
 // NB: we use a specific `T` for this `Closure<T>` impl block to avoid every
 // call site having to provide an explicit, turbo-fished type like
-// `Closure::<FnOnce()>::once(...)`.
+// `Closure::<dyn FnOnce()>::once(...)`.
 impl Closure<dyn FnOnce()> {
     /// Create a `Closure` from a function that can only be called once.
     ///
     /// Since we have no way of enforcing that JS cannot attempt to call this
-    /// `FnOne(A...) -> R` more than once, this produces a `Closure<FnMut(A...)
+    /// `FnOne(A...) -> R` more than once, this produces a `Closure<dyn FnMut(A...)
     /// -> R>` that will dynamically throw a JavaScript error if called more
     /// than once.
     ///
@@ -404,7 +404,7 @@ impl Closure<dyn FnOnce()> {
     ///
     /// // Create a `Closure` from `f`. Note that the `Closure`'s type parameter
     /// // is `FnMut`, even though `f` is `FnOnce`.
-    /// let closure: Closure<FnMut() -> String> = Closure::once(f);
+    /// let closure: Closure<dyn FnMut() -> String> = Closure::once(f);
     /// ```
     pub fn once<F, A, R>(fn_once: F) -> Closure<F::FnMut>
     where