WASM–JavaScript Interop Vocabulary

Vocabulary Reference

WebAssembly.instantiate()

The primary browser API to compile and instantiate a .wasm binary. Accepts a BufferSource or WebAssembly.Module and an optional import object; resolves with the compiled module and instance.

wasm-bindgen

A Rust tool that auto-generates JavaScript glue code so Rust-compiled WASM can pass rich types (strings, structs, closures) to and from JavaScript without manual memory management.

import object

A plain JavaScript object passed to WebAssembly.instantiate() that supplies host functions and memory to the WASM module's declared imports.

the WASM module exposes

A common phrase indicating that a function or value is listed in the module's export section and is callable from JavaScript after instantiation.

passing data between WASM and JS

Because WASM functions only accept numbers, passing strings or arrays requires writing data into linear memory and passing pointers — or using wasm-bindgen/Emscripten glue to automate this.

memory.grow()

A WASM instruction (and JavaScript WebAssembly.Memory method) that increases linear memory by a given number of 64 KiB pages.