Quick Start

Get started with Mozhi in 5 minutes. This guide assumes you've already installed the Mozhi toolchain.

Your First Program

Create a file called hello.mz:

# hello.mz
echo("Hello, World!")

Run it:

$ mozhi run hello.mz
Hello, World!

Variables and Types

# Variables are declared by assignment
name = "Mozhi"
age = 20
price = 99.99
active = true

# Constants use the const keyword
const PI = 3.14159

# Explicit type annotations (optional)
count: int = 0
label: string = "default"

echo(name, " is ", age, " years old")

Functions

# Named function
fn add(a, b) {
    return a + b
}

# Function with type annotations
fn greet(name: string) -> string {
    return "Hello, " + name
}

# Anonymous function (lambda)
double = fn(x) { return x * 2 }

echo(add(3, 4))        # 7
echo(greet("Alice"))    # Hello, Alice
echo(double(5))        # 10

Control Flow

# If / else
if age >= 18 {
    echo("Adult")
} else {
    echo("Minor")
}

# While loop
i = 0
while i < 5 {
    echo("i = ", i)
    i += 1
}

# For loop (C-style)
for j = 0; j < 3; j += 1 {
    echo("j = ", j)
}

# For-in loop
fruits = ["apple", "banana", "cherry"]
for fruit in fruits {
    echo(fruit)
}

# Match (pattern matching)
x = 2
match x {
    1 => echo("One")
    2 => echo("Two")
    3 => echo("Three")
    _ => echo("Other")
}

Structs and Traits

# Define a struct
struct User {
    name: string
    age: int
}

# Define a trait
trait Greetable {
    fn greet()
}

# Implement the trait for User
impl Greetable for User {
    fn greet() {
        echo("Hi, I'm ", name)
    }
}

# Create an instance
user = User { name: "Alice", age: 30 }
user.greet()  # Hi, I'm Alice

Arrays and Strings

# Arrays
nums = [1, 2, 3, 4, 5]
echo(len(nums))     # 5
echo(nums[0])        # 1
nums.push(6)         # add element
last = nums.pop()      # remove and return last

# Strings
name = "Mozhi"
greeting = "Hello, " + name
echo(len(name))      # 4

Error Handling

fn divide(a, b) {
    if b == 0 {
        throw Error { message: "Division by zero" }
    }
    return a / b
}

try {
    result = divide(10, 0)
} catch err {
    echo("Error: ", err.message)
}

Imports & Libraries (v2.3+)

# Three import styles:
import html                        # wildcard (func() directly)
import http from "mozhi-http"      # namespace (http.func())
import my from "mylib.mz"          # file path (my.func())

# Libraries auto-download from GitHub on first use!
page = html_page("My Site", html_h1("Hello!"))
echo(page)

File I/O & Shell (v2.4+)

# File operations
write_file("data.txt", "Hello!")
content = read_file("data.txt")
echo(content)

# Run shell commands
output = run("ls -la")
echo(output)

# Run other language files
echo(run_c("program.c"))      # compile & run C
echo(run_py("script.py"))     # run Python
echo(run_sh("script.sh"))     # run shell script

HTTP Server (v2.4+)

import http from "mozhi-http"

fn handler(method, path) {
    # Serve static files from public/ directory
    return http.http_serve_static(path, "public")
}

server = http.http_start(8080)
http.http_serve_loop(server, handler)

REPL

Start the interactive REPL:

$ mozhi
Mozhi REPL
Version 2.0

> x = 10
> echo(x)
10
> fn double(n) { return n * 2 }
> double(5)
10
> exit

Next Steps

• Read the full Language Specification
• Explore example programs
• Learn about the Package Manager
• Join the community on GitHub Issues