Geam APIs

Core APIs for Gleam programs running on Geam, the Rust runtime and embedding layer for Gleam.

gleam add geam

Future

Use geam/future to compose work from Rust async functions:

import geam/future.{type Future}

pub fn answer() -> Future(Int) {
  use value <- future.map(future.ready(21))
  value * 2
}

Calling answer returns work. The Rust host explicitly drives it to obtain 42. Reusing the same Future shares its result rather than repeating the operation. map transforms a result, then continues with another Future, and all combines independent work in input order.

See the Future guide and Rust embedding guide for the complete source and host workflow.

Runtime Support

These APIs are implemented by Geam. This package is versioned independently of the Geam runtime.

Implementations for the Erlang and JavaScript runtimes are not yet available.