https://github.com/nkrkv/jzon

ReScript library to encode and decode JSON data with type safety.
https://github.com/nkrkv/jzon

json rescript

Last synced: about 1 month ago
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ReScript library to encode and decode JSON data with type safety.

• Host: GitHub
• URL: https://github.com/nkrkv/jzon
• Owner: nkrkv
• License: other
• Created: 2021-02-08T16:18:51.000Z (almost 4 years ago)
• Default Branch: master
• Last Pushed: 2024-06-03T18:34:04.000Z (8 months ago)
• Last Synced: 2024-12-14T17:05:20.093Z (about 1 month ago)
• Topics: json, rescript
• Language: ReScript
• Homepage: https://nkrkv.github.io/jzon/
• Size: 802 KB
• Stars: 76
• Watchers: 4
• Forks: 4
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE.md

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README

        
# Jzon

Jzon is a library for ReScript to encode and decode JSON data with type safety.

- 🎷 [Documentation](https://nkrkv.github.io/jzon/) 🎷

- [Changelog](./CHANGELOG.md): MIT

- [License](./LICENSE.md): MIT

## Installation

1. `yarn add rescript-jzon`

2. Add `"rescript-jzon"` item to the `dependencies` key of `bsconfig.json`

## Quick start

Imagine you have the following ReScript types to encode and decode:

```rescript

type style = {

  size: float,

  color: string,

}

type point = {

  x: float,

  y: float,

  z: float,

  style: option,

}

```

First, define their _codecs_:

```rescript

module Codecs = {

  let style = Jzon.object2(

    // Function to encode original object to linear tuple

    ({size, color}) => (size, color),

    // Function to decode linear tuple back to object

    ((size, color)) => {size, color}->Ok,

    // Field names and codecs for the tuple elements

    Jzon.field("size", Jzon.float),

    Jzon.field("color", Jzon.string),

  );

  // Similar codec for another record type

  let point = Jzon.object4(

    ({x, y, z, style}) => (x, y, z, style),

    ((x, y, z, style)) => {x, y, z, style}->Ok,

    Jzon.field("x", Jzon.float),

    Jzon.field("y", Jzon.float),

    // ... supports default values

    Jzon.field("z", Jzon.float)->Jzon.default(0.0),

    // ... may refer your other codecs

    Jzon.field("style", style)->Jzon.optional,

  )

}

```

Next, convert between the ReScript types and `Js.Json.t` with:

```rescript

let myPoint = {

  x: 1.0,

  y: 2.0,

  z: 3.0,

  style: Some({size: 4.0, color: "#fd0"}),

}

let json = myPoint->Jzon.encodeWith(Codecs.point)

```

and back with:

```rescript

let myPoint = json->Jzon.decodeWith(Codecs.point)

```