Introduction

What is Starlark?

Starlark is a small subset of Python developed by Google for their Bazel build system. If you know Python, it should be easy to learn.

Example code

The code below is an example of the syntax of Starlark. If you've ever used Python, this should look very familiar. In fact, the code above is also a valid Python code. Still, this short example shows most of the language. Starlark is indeed a very small language. - Starlark README.md

From Starlark README.md

# Define a number
number = 18

# Define a dictionary
people = {
    "Alice": 22,
    "Bob": 40,
    "Charlie": 55,
    "Dave": 14,
}

names = ", ".join(people.keys())  # Alice, Bob, Charlie, Dave

# Define a function
def greet(name):
    """Return a greeting."""
    return "Hello {}!".format(name)

greeting = greet(names)

above30 = [name for name, age in people.items() if age >= 30]

print("{} people are above 30.".format(len(above30)))

def fizz_buzz(n):
    """Print Fizz Buzz numbers from 1 to n."""
    for i in range(1, n + 1):
        s = ""
        if i % 3 == 0:
            s += "Fizz"
        if i % 5 == 0:
            s += "Buzz"
        print(s if s else i)

fizz_buzz(20)

More Starlark documentation

• Language specification (Bazel)
• Language specification (starlark-go)

Modules

We have a few modules available that are available in the global scope. See Modules for more information.