This runtime implements the bare minimum set of functions to get most C/C++ libraries that have been compiled with the "reactor" exec model running.

The only thing it allows is writing to stdout/stderr, getting the current time and getting random numbers, which should really be enough for everyone.

import { TinyWASI } from "tinywasi";

let tinywasi = new TinyWASI();

let imports = {
	<your_own_imports>,
	...tinywasi.imports
};

const { module, instance } = await WebAssembly.instantiate( <wasm_source>, imports );

tinywasi.initialize( instance );

Instantiates a new TinyWASI runtime.

• trace: boolean, optional. Wether or not to print all system calls to the console for debugging.

Initializes the runtime and WASM instance. Call this before making any other calls.

• instance: WebAssembly instance to connect to and initialize.

Array containing the functions to be imported by the WebAssembly module.
Pass this directly to WebAssembly.instantiate or add it to your own imports.

Currently TinyWASI implements the following system calls:

Implemented for the proper function of stat and isatty which are needed for printing to stdout/stderr to work correctly.

Implemented for writing to stdout and stderr. Writing to any other file descriptor returns ERRNO_BADF.

All writes to stdout (fd 1) are logged to the console using console.log.
All writes to stderr (fd 2) are logged to the console using console.error.

Implemented to make functions like time() work. Right now only the realtime clock (id 0) is supported.

Implemented to make C++ std::random_device work.

All other system calls are unimplemented and return ERRNO_NOSYS while printing an error message to the console.

None.

• typescript - for compiling the typescript source files to javascript
• @types/node - typescript definitions for node's API

Optionally:

• prettier - for code formatting using the included .prettierrc