JSON in AssemblyScript

JairusSW — Tue, 20 Jul 2021 14:44:53 +0000

Finally, AssemblyScript has a fully-functional JSON implementation. as-json implements full JSON compatibility that enables AssemblyScript to use JSON to communicate with APIs, store data, and more. In this article, I will introduce you to as-json and help you include it into your project.

Getting Started

as-json uses the same general API as the JavaScript JSON object. We can then use it just like JS. However, we must install and prep it first.

npm install json-as

--transform json-as/transform

Installation complete. Lets use some JSON! 🔥

json-test.ts

import { JSON } from 'json-as'

// Create the Schemas
// @ts-ignore
@json
class JSONSchema {
  firstName: string;
  lastName: string;
  human: boolean;
  age: i32;
  meta: Meta;
  language: string;
  location: f64[];
}

// @ts-ignore
@json
class Meta {
  country: string;
  awesome: boolean;
}

// Create the JSON object
const data: JSONSchema = {
  firstName: 'Jairus',
  lastName: 'Tanaka',
  age: 14,
  human: true,
  meta: {
    country: 'US',
    awesome: true
  },
  language: 'english',
  location: [-43.130850291, 32.926401705]
};

// Now, encode and decode
const encoded: string = JSON.stringify(data)
console.log(`Encoded: ${encoded}`)
const decoded = JSON.parse<JSONSchema>(encoded)
console.log(`Decoded:`)
console.log(`{`);
console.log(` firstName: ${decoded.firstName},`);
console.log(` lastName: ${decoded.lastName},`);
console.log(` age: ${decoded.age},`);
console.log(` human: ${decoded.human},`);
console.log(` meta: {`);
console.log(`   country: ${decoded.meta.country},`);
console.log(`   awesome: ${decoded.meta.awesome}`);
console.log(` },`);
console.log(` language: ${decoded.language}`);
console.log(` location: [${decoded.location[0]}, ${decoded.location[1]}]`);
console.log(`}`);

Note: If you are not running in WASI, use as-console instead.

So, json-as serialized and deserialized JSON. Lets see if it was correct.

json-test.ts

import { JSON } from 'json-as'

// Create the Schemas
// @ts-ignore
@json
class JSONSchema {
  firstName: string;
  lastName: string;
  human: boolean;
  age: i32;
  meta: Meta;
  language: string;
  location: f64[];
}

// @ts-ignore
@json
class Meta {
  country: string;
  awesome: boolean;
}

// Create the JSON object
const data: JSONSchema = {
  firstName: 'Jairus',
  lastName: 'Tanaka',
  age: 14,
  human: true,
  meta: {
    country: 'US',
    awesome: true
  },
  language: 'english',
  location: [-43.130850291, 32.926401705]
};

// Now, encode and decode
const encoded: string = JSON.stringify(data)
const decoded = JSON.parse<JSONSchema>(encoded)
// We perform an equality check
if (encoded == JSON.stringify(decoded)) {
  console.log('Yay! JSON-AS works! 😄')
} else {
  console.log('Oof. JSON-AS died.😖')
}

Yay! JSON is now working for AssemblyScript. Go ahead and mess around with it and let me know what you make.
With the up-and-coming release of JSON-AS v0.2.0, full dynamic objects and arrays will be supported.
NPM: https://www.npmjs.com/package/json-as
GitHub: https://github.com/aspkg/as-json
Thanks for reading 😁

What is AssemblyScript?

JairusSW — Mon, 12 Jul 2021 18:34:40 +0000

AssemblyScript — a variant of TypeScript that compiles to WebAssembly. Since it is compiled, it outperforms JavaScript in some cases. AS follows the TypeScript syntax as closely as possible and even adds more features to it. AssemblyScript allows us to write fast WebAssembly for the Web and Server without learning another language.

AssemblyScript is very easy to use. All you need to do is install it via NPM.

Try it out online: Online editor

~ npm i assemblyscript --save-dev
~ npx asinit .
~ npm i

What did that do? First of all, it installed both the loader and the compiler. Secondly, it made a template project with an add function. Now, we just need to compile it to WebAssembly.

~ npm run asbuild

So, if you check out the /build folder, there are the .wasm files that were built. NodeJS and JavaScript both provide a way to run WebAssembly files and AssemblyScript provides its own loader to work with the code. To start our code, we need another file

test.js

const wasmModule = require('./index')
// This works just like a normal module
console.log(wasmModule.add(2,9))
// -- 11

Now, run it!

~ node test.js

It should have outputted the number 11.

JavaScript code for the add function would look like this:

function add(a, b) {
    return a + b
}
module.exports = {
    add: add
}

The AssemblyScript code looks like this:

export function add(a: i32, b: i32): i32 {
    return a + b;
}

Pretty similar, right? When we compile it, we can require it just like a normal JavaScript file. Keep in mind that WebAssembly is sandboxed which means it can’t access the system, make HTTP requests, or log to the console. However, AssemblyScript supports both WASI and JS bindings (calling JS from AS).

If you have any questions or comments, feel free to comment or join the AssemblyScript Discord. Or, check out the website.😉

P.S: There is a tutorial at https://jtanaka.gitbook.io/guide/

Forem: AssemblyScript

JSON in AssemblyScript

Getting Started

What is AssemblyScript?