Package Exports

json-as/transform/lib/index.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (json-as) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

AS-JSON

JSON for AssemblyScript focused on performance, low-overhead, and ease-of-use.

Installation

npm install json-as

Add the transform to your asc command (e.g. in package.json)

--transform json-as/transform

Alternatively, add it to your asconfig.json

{
  "options": {
    "transform": ["json-as/transform"]
  }
}

Usage

import { JSON } from "json-as/assembly";

// @json or @serializable work here
@json
class Vec3 {
  x!: f32;
  y!: f32;
  z!: f32;
}

@json
class Player {
  firstName!: string;
  lastName!: string;
  lastActive!: i32[];
  age!: i32;
  pos!: Vec3 | null;
  isVerified!: boolean;
}

const player: Player = {
  firstName: "Emmet",
  lastName: "West",
  lastActive: [8, 27, 2022],
  age: 23,
  pos: {
    x: 3.4,
    y: 1.2,
    z: 8.3
  },
  isVerified: true
};

const stringified = JSON.stringify<Player>(player);

const parsed = JSON.parse<Player>(stringified);

Deviations from the spec

This implementation does not hold strongly to the JSON specification. Rather, design and behavior are inspired by the JSON implementation found in Google's v8 engine.

No support for dynamic types
Unsafe by design--parser assumes valid JSON
Partial whitespace support--parser prefers speed over handling whitespace effectively. Users may use the removeWhitespace function provided by json-as/src/util.ts
Is not based off of the official spec, but rather the behavior of the JSON C implementation found in google's v8 engine
Support for scientific notation on integers. Float support coming soon.

Implemented features

Fully supports:

Strings
Integers
Floats (Scientific notation not implemented)
Booleans
Arrays
Objects
Date
Null

Performance

Number parsing speed has doubled over the last 5 versions due to the use of a atoi_fast function found in assembly/util.ts. This can be further optimized with SIMD.

String serialization has more than tripled in performance (+360%). The algorithm was rewritten for less if statements and more traps.

String deserialization was quadrupled from 3.4m ops to 14.8 ops (435%). It went from using .replaceAll to a specialized algorithm.

Schema (object) parsing is being optimized on GitHub and should be at least doubled if not tripled. (Current speed of barely-optimized version is 6.9m ops) This is due to taking advantage of the types with a type map and eliminating extra checking.

Serialize Object (Vec3): 6.7m ops/5s

Deserialize Object (Vec3): 5.1m ops/5s

Serialize Array (int[]): 6.6m ops/5s

Deserialize Array (int[]): 8.6m ops/5s

Serialize String (5): 5.9m ops/5s

Deserialize String (5): 16.3m ops/5s

Issues

Please submit an issue to https://github.com/JairusSW/as-json/issues if you find anything wrong with this library