decode

Ergonomic dynamic decoders for Gleam!

gleam add decode

import decode/zero as decode
import gleam/dynamic.{type Dynamic}


pub type User {
  User(name: String, email: String, is_admin: Bool)
}

/// Decode data of this shape into a `User` record.
///
/// {
///   "name" -> "Lucy",
///   "email" -> "lucy@example.com",
///   "is-admin" -> true
/// }
///
pub fn run(data: Dynamic) {
  let decoder = {
    use name <- decode.field("name", decode.string)
    use email <- decode.field("email", decode.string)
    use is_admin <- decode.field("is-admin", decode.bool)
    decode.success(User(name:, email:, is_admin:))
  }

  decode.run(data, decoder)
}

Or, alternatively:

import decode
import gleam/dynamic.{type Dynamic}

pub type User {
  User(name: String, email: String, is_admin: Bool)
}

/// Decode data of this shape into a `User` record.
///
/// {
///   "name" -> "Lucy",
///   "email" -> "lucy@example.com",
///   "is-admin" -> true
/// }
///
pub fn run(data: Dynamic) {
  let decoder =
    decode.into({
      use name <- decode.parameter
      use email <- decode.parameter
      use is_admin <- decode.parameter
      User(name, email, is_admin)
    })
    |> decode.field("name", decode.string)
    |> decode.field("email", decode.string)
    |> decode.field("is-admin", decode.bool)

  decoder
  |> decode.from(data)
}

For more documentation and examples view https://hexdocs.pm/decode.