Calling Closures via WebAssembly

What is Closures?

The official Rust book, by Steve Klabnick and Carol Nichols, defines Closures as follows:

“Closures are anonymous functions which you can save in a variable or can be passed as arguments to other functions.”

MDN defines a closure for JavaScript as follows:

“A closure is the combination of a function and lexical environment within which that function was declared.”

In general, Closures are self-contained blocks of functionality that are tossed around and used in the code. They can capture and store references to the variables from the context in which they’re defined. Closures and functions are similar except for a subtle difference. Closures will capture the state when it’s first created. Then, ...