$ whois gleam

Gleam

first released in 2016 · by Louis Pilfold

$ guessprog --inspect gleam

year: 2016
paradigm: functional
family: erlang
memory: automatic gc
binding: static
safety: strong

GLEAM(7)

AUTHORS: Louis Pilfold
HISTORY: Louis Pilfold started Gleam in 2016, wanting the reliability of the Erlang virtual machine with the safety of a modern static type system. Gleam compiles to Erlang, to run on the BEAM alongside Erlang and Elixir code, and also to JavaScript. Its compiler is written in Rust and the language is deliberately small: no null, no exceptions, no macros and no type classes. Version 1.0 was released in March 2024.
USAGE: A young but fast-growing language, popular with developers who like functional programming and the BEAM. It is used for web back ends and services, and its friendly community and error messages are often praised.
SEE ALSO: Gleam on Wikipedia ↗

$ cat pets.gleam

import gleam/int
import gleam/io
import gleam/list

pub type Pet {
  Dog(name: String)
  Cat(name: String, lives: Int)
}

fn describe(pet: Pet) -> String {
  case pet {
    Dog(name) -> name <> " says woof"
    Cat(name, lives) -> name <> " has " <> int.to_string(lives) <> " lives"
  }
}

pub fn main() {
  [Dog("Rex"), Cat("Tom", 9)]
  |> list.map(describe)
  |> list.each(io.println)
}