YGleam

Gleam bindings to Yjs

Library state

The bidnings to YDoc, YMap, YArray, YUndoManager and their event listeners are solid. They are used in production daily at Nestful.

Other parts of the code were written on a best-effort basis and are untested, as we currently do not use them in Nestful. PRs welcome.

API state

This library binds from a functional, immutable, type-safe language (Gleam), to a dynamic JavaScript API. This proves challenging. We are fairly close to a 1.0, with a nice, ergonomic, as close to riding-on-a-cloud as possible, but not quite there yet. Expect breaking changes.

Do open an issue if you have an API suggestion.

Usage

Currently this library is almost a one-to-one FFI to Yjs, so first please consult their respective docs at https://yjs.dev.

Here’s an example for saving some Pets:

import gleam/dynamic/decode.{type Dynamic}
import ygleam/y
import ygleam/y_doc
import ygleam/y_map
import ygleam/y_array

type Pet {
    Pet(name: String, species: String)
}

fn encode_pet(pet: Pet) -> y.Value {
    let ymap = y_map.new()
    ymap
    |> y_map.set("name", y.string(pet.name))
    |> y_map.set("species", y.string(pet.species))
    |> y.map
}

fn pet_decoder() {
    use name <- decode.field("name", decode.string)
    use species <- decode.field("species", decode.string)
}

fn decode_pet(dyn_pet: Dynamic) {
    decode.run(dyn_pet, y_map.decoder())
    |> result.map(y_map.to_json)
    |> result.then(decode.run(_, pet_decoder()))
}

fn decode_pet_name(dyn_pet: Dynamic) -> String {
    decode.run(dyn_pet, y_map.decoder())
    |> result.map(y_map.get("species"))
    |> result.then(decode.run(_, decode.string))
}

let ydoc = y_doc.new()

let pets = y_doc.get_array(ydoc, "pets")

[
    Pet(name: "Doggo", species: "Dog"),
    Pet(name: "Catto", species: "Cat")
]
|> list.map(encode_pet)
|> y_array.push(pets)

get(pets, 0)
|> decode_pet
|> echo

get(pets, 1)
|> decode_pet_name
|> echo

Sponsored by Nestful

YGleam is developed for and sponsored by Nestful, the best app there is to manage your own time.