Crate wasm_bindgen 

Runtime support for the wasm-bindgen tool

This crate contains the runtime support necessary for wasm-bindgen the attribute and tool. Crates pull in the #[wasm_bindgen] attribute through this crate and this crate also provides JS bindings through the JsValue interface.

Features

enable-interning

Enables the internal cache for [wasm_bindgen::intern].

This feature currently enables the std feature, meaning that it is not compatible with no_std environments.

std (default)

Enabling this feature will make the crate depend on the Rust standard library.

Disable this feature to use this crate in no_std environments.

strict-macro

All warnings the #[wasm_bindgen] macro emits are turned into hard errors. This mainly affects unused attribute options.

Deprecated features

serde-serialize

Deprecated: Use the serde-wasm-bindgen crate instead.

Enables the JsValue::from_serde and JsValue::into_serde methods for serializing and deserializing Rust types to and from JavaScript.

spans

Deprecated: This feature became a no-op in wasm-bindgen v0.2.20 (Sep 7, 2018).

Re-exports

pub use crate::convert::IntoJsGeneric;

pub use crate::convert::JsGeneric;

Modules

closure

Support for closures in wasm-bindgen

convert

⚠️ Unstable

prelude

A module which is typically glob imported.

sys

JavaScript system types that are re-exported by js-sys.

Macros

link_to

This macro takes a JS module as input and returns a URL that can be used to access it at runtime.

Structs

Clamped

A wrapper type around slices and vectors for binding the Uint8ClampedArray array in JS.

JsError

Convenience type for use on exported fn() -> Result<T, JsError> functions, where you wish to throw a JavaScript Error object.

JsStaticDeprecated

Wrapper type for imported statics.

JsThreadLocal

Wrapper type for imported statics.

JsValue

Representation of an object owned by JS.

Parent

Storage wrapper for the auto-injected parent field on a struct that declares #[wasm_bindgen(extends = Parent)].

Traits

ErasableGeneric

Private marker trait for erasable generics - types with this trait have the same repr for all generic param values, and can therefore be transmuted on the singular Repr type representation on ABI boundaries.

JsCast

A trait for dynamic checked and unchecked casting between JS types.

UnwrapThrowExt

An extension trait for Option<T> and Result<T, E> for unwrapping the T value, or throwing a JS error if it is not available.

Functions

exports

Returns a handle to this Wasm instance’s WebAssembly.Instance.prototype.exports

externref_heap_live_count

Get the count of live externrefs / JsValues in wasm-bindgen’s heap.

function_table

Returns a handle to this Wasm instance’s WebAssembly.Table which is the indirect function table used by Rust

instance

Returns a handle to this Wasm instance’s WebAssembly.Instance. This is only available when the final Wasm app is built with --target no-modules, --target web, --target deno or --target nodejs. It is unavailable for --target bundler.

intern

Interns Rust strings so that it’s much faster to send them to JS.

memory

Returns a handle to this Wasm instance’s WebAssembly.Memory

module

Returns a handle to this Wasm instance’s WebAssembly.Module. This is only available when the final Wasm app is built with --target no-modules, --target web, --target deno or --target nodejs. It is unavailable for --target bundler.

throw_str

Throws a JS exception.

throw_val

Rethrow a JS exception

unintern

Removes a Rust string from the intern cache.