Skip to main content

Quick Start

Create a file named hello.jde:

let x = 10
let y = 32
let answer = x + y
print(answer)

Run it:

jade run hello.jde

Output:

42

jade run also accepts the name of a script defined in jade.toml. With no argument at all, it runs the current project's entry file. See the CLI Reference.

Seeing what a program left behind​

Pass --verbose to print every global variable after the program finishes:

jade run hello.jde --verbose

Output:

42
Grammar = {"new": <builtin new>}
answer = 42
x = 10
y = 32

The program's own output comes first. The globals follow, in alphabetical order. Built-in globals such as Grammar appear alongside the ones you defined.

A slightly bigger program​

Here is greet.jde, which uses functions, f-strings, arrays, and a for loop:

fn greet(name) {
    return f"Hello, {name}!"
}

let people = ["Ada", "Grace", "Alan"]

for p in people {
    print(greet(p))
}
jade run greet.jde
Hello, Ada!
Hello, Grace!
Hello, Alan!

To type-check without running:

jade check greet.jde
greet.jde: ok

Compiling to a binary​

The same file compiles to a native executable. The result runs on its own, with no copy of jade installed:

jade build greet.jde -o greet
./greet
built: greet
Hello, Ada!
Hello, Grace!
Hello, Alan!

jade run and jade build are two engines for one language. A program means the same thing under either one.

Starting a project​

Once a program outgrows a single file, jade new sets up a project for you:

jade new myapp
created: myapp/
  jade.toml
  main.jde
  .gitignore

Get started:
  cd myapp
  jade run
cd myapp
jade run
Hello from myapp!

jade run with no argument runs the entry file named in jade.toml. From here on, it is the only run command you need.

Calling a model​

This step is the reason Jade exists. A prompt is a value. The ? operator sends it to your provider. The |> int stage makes the result an int, or raises if it cannot:

prompt p = "How many moons does Mars have? Reply with just the number."

let n = ?p |> int
print(n + 1)

This program needs an inference provider registered first, so run jade register before you try it. See LLM Integration for the whole picture.