The Gleam Programming Language
The power of a type system, the expressiveness of functional
programming, and the reliability of the highly concurrent, fault
tolerant Erlang runtime, with a familiar and modern syntax.
import gleam/io
pub fn main() {
io.println("hello, friend!")
}Reliable and scalable
Running on the battle-tested Erlang virtual machine that powers
planet-scale systems such as WhatsApp and Ericsson, Gleam is ready for
workloads of any size.
Thanks to its multi-core actor based concurrency system that can run
millions of concurrent green threads, fast immutable data
structures, and a concurrent garbage collector that never stops
the world, your service can scale and stay lightning fast with ease.
pub fn main() -> Nil {
// Run loads of green threads, no problem
list.range(0, 200_000)
|> list.each(spawn_greeter)
}
fn spawn_greeter(i: Int) {
process.spawn(fn() {
let n = int.to_string(i)
io.println("Hello from " <> n)
})
}Ready when you are
Gleam comes with compiler, build tool, formatter, editor integrations,
and package manager all built in, so creating a Gleam project is just
running gleam new
As part of the wider BEAM ecosystem, Gleam programs can use thousands of
published packages, whether they are written in Gleam, Erlang, or
Elixir.
➜ (main) gleam add gleam_json
Resolving versions
Downloading packages
Downloaded 2 packages in 0.01s
Added gleam_json v0.5.0
➜ (main) gleam test
Compiling thoas
Compiling gleam_json
Compiling app
Compiled in 1.67s
Running app_test.main
.
1 tests, 0 failuresHere to help
No null values, no exceptions, clear error messages, and a practical
type system. Whether you’re writing new code or maintaining old code,
Gleam is designed to make your job as fun and stress-free as possible.
error: Unknown record field
┌─ ./src/app.gleam:8:16
│
8 │ user.alias
│ ^^^^^^ Did you mean `name`?
The value being accessed has this type:
User
It has these fields:
.name
Multilingual
Gleam makes it easy to use code written in other BEAM languages such as
Erlang and Elixir, so there’s a rich ecosystem of thousands of open
source libraries for Gleam users to make use of.
Gleam can additionally compile to JavaScript, enabling you to use your
code in the browser, or anywhere else JavaScript can run. It also
generates TypeScript definitions, so you can interact with your Gleam
code confidently, even from the outside.
@external(erlang, "Elixir.HPAX", "new")
pub fn new(size: Int) -> Table
pub fn register_event_handler() {
let el = document.query_selector("a")
element.add_event_listener(el, fn() {
io.println("Clicked!")
})
}Friendly 💜
As a community, we want to be friendly too. People from around the
world, of all backgrounds, genders, and experience levels are welcome
and respected equally. See our community code of conduct for more.
Black lives matter. Trans rights are human rights. No nazi bullsh*t.
You’re still here?
Well, that’s all this page has to say. Maybe you should go read the language tour!
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