雨山

Gleam cheat sheet

Intro

Create a new project:

gleam new some_name

Run a project (from inside the project directory):

gleam run

Syntax example:

import gleam/io

pub fn main() {
  io.println("Hello, world!")
}

Printing to the command line can be done either with (e.g.) io.println or the simple echo keyword (which also prints the line):

import gleam/io

pub fn main() {
  io.println("Hello, world!")
  echo "Hello, world!"
}

Import parts of the standard library:

import gleam/float
import gleam/int
import gleam/string

pub fn main() {
  echo string.reverse("Hello, world!")
  echo int.max(234, 567)
  echo float.max(2.34, 5.67)
}

Numbers

One really horrible thing is: there are different operators for working with integers and floats. For example, the simple + can be used with integers but not with floats; instead, floats must be added with +., like this:

pub fn main() {
  echo 234 + 567
  echo 2.34 +. 5.67
}

Strings

Strings:

• can be multi-line
• can be concated with <>

pub fn main() {
  echo "foo" <> "bar"

  echo "
    This is
    a multi-line
    string.
  "
}