Your First Lumen Program

The fastest way to get oriented is to let Lumen generate a starter script for you.

Generate a starter program

lumen --introduction

This writes a file called helloworld.lmn in the current directory:

println 'Hello, world!'

name = ''
print 'What`s your name? '
inputStr &name

greeting = 'Hello, ' .. name .. '!'
println greeting

It also prints a short welcome message pointing you at the next steps.

Run it

lumen helloworld.lmn

Hello, world!
What`s your name? Ryan
Hello, Ryan!

When you run a .lmn file with no flags, Lumen compiles and executes it in one step — you don’t need to invoke the compiler and VM separately unless you want to (see CLI Reference).

Explore the built-in examples

Lumen ships with a handful of example programs baked into the binary. List them:

lumen --examples

Available examples:
  age               Age calculator
  infinite-loop     Infinite loop demonstrating labels and jumps
  temperature       Temperature converter
  fizzbuzz          Classical FizzBuzz algorithm

Generate an example:
  lumen --examples <name>

Generate one to disk:

lumen --examples fizzbuzz

✨ Created 'fizzbuzz.lmn'!
👉 Run it with: lumen fizzbuzz.lmn

And run it:

lumen fizzbuzz.lmn

Each of these is walked through in detail in the Examples chapter.

What’s next

• Read through the Language Guide to learn Lumen’s syntax feature by feature.
• Or jump straight to the CLI Reference to see every flag lumen supports.