Creating a WIT Specification for the power-of Example

Before we do any coding, let’s first define our interface. WIT is an Interface Definition Language (IDL) used to describe Wasm modules. It is provided in files with the .wit extension.

This example will compute x^y (that is, "x to the power of y").

In a new work directory, create a new file called power.wit in your text editor, and add this content:

power-of: func(b: s32, exp: s32) -> s32

This function will take two signed 32-bit integers as arguments (the base b and the exponent exp) and return a single, signed 32-bit integer.

Go ahead and save the file.

Now we’re ready to write some code.

• If you'd like to learn about implementing this example in C, please look here.
• If you'd like to learn about implementing this example in Rust, please look here.