Gleam is a general-purpose, concurrent, functional high-level programming language that compiles to Erlang or JavaScript source code.
Gleam is a statically-typed language, which is different from the most popular languages that run on Erlang’s virtual machine BEAM, Erlang and Elixir. Gleam has its own type-safe implementation of OTP, Erlang's actor framework. Packages are provided using the Hex package manager, and an index for finding packages written for Gleam is available.
History
The first numbered version of Gleam was released on April 15, 2019.7 Compiling to JavaScript was introduced with version v0.16.8
In 2023 the Erlang Ecosystem Foundation funded the creation of a course for learning Gleam on the learning platform Exercism.9
Version v1.0.0 was released on March 4, 2024.10
Features
Gleam includes the following features, many common to other functional programming languages:11
- Result type for error handling
- Immutable objects
- Algebraic data types
- Pattern matching
- No null pointers
- No implicit type conversions
Example
A "Hello, World!" example:
import gleam/io pub fn main() { io.println("hello, world!") }Gleam supports tail call optimization:12
pub fn factorial(x: Int) -> Int { // The public function calls the private tail recursive function factorial_loop(x, 1) } fn factorial_loop(x: Int, accumulator: Int) -> Int { case x { 1 -> accumulator // The last thing this function does is call itself _ -> factorial_loop(x - 1, accumulator * x) } }Implementation
Gleam's toolchain is implemented in the Rust programming language.13 The toolchain is a single native binary executable which contains the compiler, build tool, package manager, source code formatter, and language server. A WebAssembly binary containing the Gleam compiler is also available, enabling Gleam code to be compiled within a web browser.
External links
References
"Gleam Homepage". 2024. https://gleam.run/ ↩
Krill, Paul (March 5, 2024). "Gleam language available in first stable release". InfoWorld. Retrieved March 26, 2024. https://www.infoworld.com/article/3713460/gleam-language-available-in-first-stable-release.html ↩
Eastman, David (June 22, 2024). "Introduction to Gleam, a New Functional Programming Language". The New Stack. Retrieved July 29, 2024. https://thenewstack.io/introduction-to-gleam-a-new-functional-programming-language/ ↩
De Simone, Sergio (March 16, 2024). "Erlang-Runtime Statically-Typed Functional Language Gleam Reaches 1.0". InfoQ. Retrieved March 26, 2024. https://www.infoq.com/news/2024/03/gleam-erlang-virtual-machine-1-0/ ↩
Getting to know Actors in Gleam – Raúl Chouza. Code BEAM America. March 27, 2024. Retrieved May 6, 2024 – via YouTube. https://www.youtube.com/watch?v=WaHx6n2UZJg ↩
"Introducing the Gleam package index – Gleam". gleam.run. Retrieved May 7, 2024. https://gleam.run//news/introducing-the-gleam-package-index/ ↩
"Hello, Gleam! – Gleam". gleam.run. Retrieved May 6, 2024. https://gleam.run//news/hello-gleam/ ↩
"v0.16 – Gleam compiles to JavaScript! – Gleam". gleam.run. Retrieved May 7, 2024. https://gleam.run//news/v0.16-gleam-compiles-to-javascript/ ↩
Alistair, Woodman (December 2023). "Erlang Ecosystem Foundation Annual General Meeting 2023 Chair's Report". https://erlef.org/public_records/ ↩
"Gleam version 1 – Gleam". gleam.run. Retrieved May 7, 2024. https://gleam.run//news/gleam-version-1/ ↩
Eastman, David (June 22, 2024). "Introduction to Gleam, a New Functional Programming Language". The New Stack. Retrieved July 29, 2024. https://thenewstack.io/introduction-to-gleam-a-new-functional-programming-language/ ↩
"Tail Calls". The Gleam Language Tour. Retrieved March 26, 2024. https://tour.gleam.run/flow-control/tail-calls/ ↩
"gleam-lang/gleam". Gleam. May 6, 2024. Retrieved May 6, 2024. https://github.com/gleam-lang/gleam ↩