Your First Program

Let the interpreter write a starter script for you:

lumen --introduction

This creates helloworld.lmn in the current directory:

println('Hello, world!')

print('What`s your name? ')
name = inputStr()

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

Run it:

lumen helloworld.lmn

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

What happened

1. lumen helloworld.lmn compiled the script to helloworld.lmn.bin and immediately ran it. See CLI Reference to do the two steps separately.
2. println('...') and print('...') are built-in functions. println appends a newline, print does not.
3. inputStr() reads one whitespace-delimited word from standard input and returns it, so it is used on the right-hand side of an assignment.
4. .. joins strings. Numbers are converted automatically.

The backtick in What`s is only a habit: \' also works inside a single-quoted string. See Strings.

Next steps

• Generate the bundled programs with lumen --examples <name> (see Examples).
• Learn the language topic by topic.
• Step through the program with lumen helloworld.lmn --debugger, see Interactive Debugger.