Getting Started with Jarlang

Welcome!

Jarlang is a warrior-themed, beginner-friendly language for learning programming and experimenting with new ideas. Its syntax is playful, but its features are powerful—perfect for both new coders and creative tinkerers.

Why Jarlang?

• Simple, readable syntax with themed keywords.
• Easy to declare variables, write functions, and control flow.
• Comes with a rich standard library and test helpers.
• Great for learning, teaching, and rapid prototyping.

1. Running Jarlang

To run a .vase file, use the provided runner script:

./run.sh

Then use the !run command in the REPL:

!run yourfile.vase

2. Language Concepts Tutorial

Variables

Declare with wield:

wield x 10
wield name "JarKnight"

Types: Ints, Doubles, Strings

wield a 42      # int
wield b 3.14    # double
wield s "hello" # string

Conditionals

wield n 5
judge n > 0 mend chant "positive"
orjudge n == 0 mend chant "zero"
orjudge mend chant "negative"

Functions & Function Defining

forge add(a, b) {
  mend a + b
}
chant add(2, 3)  # prints 5

Loops

While loop: lest

wield i 0
lest i < 3 {
  chant i
  i = i + 1
}

For loop: endure

endure wield j 0; j < 3; j = j + 1 {
  chant j
}

Strings & Operations

wield greeting "Hello, " + name
chant greeting

Importing & Using the Standard Library

summon "stdlib.vase"
chant commune(3, 4)  # prints 7.0

3. Standard Library Highlights

Jarlang's standard library includes many helpers for math, strings, and more. Here are some favorites:

• max(a, b) — Get the maximum of two numbers.
  

  chant max(7, 3)  # prints 7

• clamp(x, lo, hi) — Restrict a value to a range.
  

  chant clamp(15, 0, 10)  # prints 10

• fact(n) — Compute factorial.
  

  chant fact(5)  # prints 120

• fib(n) — Get the nth Fibonacci number.
  

  chant fib(7)  # prints 13

• concat(a, b) — Concatenate strings.
  

  chant concat("Jar", "Knight")  # prints JarKnight

• is_prime(n) — Test for primality.
  

  chant is_prime(13)  # prints 1

See the full list for more!

4. Tips & Best Practices

• Use chant to print values and debug your code.
• Write small functions with forge and mend.
• Import stdlib.vase for extra helpers.
• Use testlib.vase for writing and running tests.
• Read the Syntax Reference for more details.