README.md

The json I/O example

In this example, we demonstrate how to use JSON to call Rust functions in SSVM from JavaScript. Read about Rust Functions in Node.js.

Prerequisites

If you have not done so already, follow these simple instructions to install Rust, Node.js, SSVM, and ssvmup.

Create new project

$ cargo new --lib json_io
$ cd json_io

Change the cargo config file

The Cargo.toml file shows the dependencies. Note the dependency for wasm-bindgen, which is required for invoking these Rust functions from JavaScript. The dependency for serde and serde-json allows us to work with JSON strings to represent complex data types.

Write Rust code

The src/lib.rs file contains a few Rust functions that showcase using JSON for input / output parameters. Multiple parameters and return values are represented in tuples.

Build the WASM bytecode

$ ssvmup build --enable-aot

Node.js app

The node/app.js file shows how to call the Rust functions, running inside the Second State VM (SSVM), from JavaScript inside Node.js.

Test

node app.js

Result

62.831802
50.0
[0.5,-3.0,true]
{"points":[{"x":1.5,"y":3.8},{"x":2.5,"y":5.8}],"valid":true,"length":2.2360682,"desc":"A thin red line"}