Modules

Modules help organize code into reusable units.

Module Declaration

module my_module

# Module code here

Importing Modules

Basic Import

import std
import math

Import with Alias

import ai as ml
import chain as web3

Import Specific Items

# Coming soon
import { add, subtract } from math

Module Structure

module calculator

fn add(a: i32, b: i32) -> i32 {
  return a + b
}

fn subtract(a: i32, b: i32) -> i32 {
  return a - b
}

fn multiply(a: i32, b: i32) -> i32 {
  return a * b
}

Using Imported Modules

import calculator

fn main() {
  let result = calculator.add(5, 3)
  print(result)  # 8
}

main()

Standard Library Modules

Core Module

import core

# Core utilities (coming soon)
let result = core.format("Hello, {}", "JOEL")

AI Module

import ai

let tensor = ai.tensor([[1, 2], [3, 4]])
let result = ai.matmul(tensor, tensor)

Chain Module

import chain

# Web3 utilities (coming soon)
let wallet = chain.create_wallet()

UI Module

import ui

component App() {
  # UI components
}

Module Paths

Local Modules

# Import from same directory
import ./utils
import ./helpers

Relative Imports

# Import from parent directory
import ../shared
import ../common

Absolute Imports

# Import from project root
import /lib/math
import /utils/helpers

Module Exports

module calculator

# Public functions (exported by default)
fn add(a: i32, b: i32) -> i32 {
  return a + b
}

# Private function (coming soon)
private fn internal_helper() {
  # Not accessible outside module
}

Examples

Creating a Module

# math.joel
module math

fn add(a: i32, b: i32) -> i32 {
  return a + b
}

fn subtract(a: i32, b: i32) -> i32 {
  return a - b
}

Using a Module

# main.joel
import math

fn main() {
  print(math.add(10, 5))      # 15
  print(math.subtract(10, 5)) # 5
}

main()

Best Practices

One module per file: Keep modules focused
Clear naming: Use descriptive module names
Organize by feature: Group related functionality
Avoid circular imports: Keep dependencies acyclic
Document exports: Comment public APIs

Next Steps

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