Module System

Flowa provides a powerful module system for organizing code across multiple files and creating reusable components.

Exporting from Modules

Use the export keyword to make variables and functions available to other files:

module_a.flowa:

export let message = "Hello from Module A";
 
export func greet(name) {
    return "Hello, " + name;
}
 
export let version = "1.0.0";

Note: Exported symbols must be declared with export before the let or func keyword.

Importing from Modules

Use the import statement with destructuring syntax to import specific symbols:

import { message, greet } from "path/to/module_a.flowa";
 
print(message);           // "Hello from Module A"
print(greet("World"));    // "Hello, World"

Module Path Resolution

Flowa resolves module paths relative to the current file or script execution directory:

// Relative to current file
import { utils } from "./utils.flowa";
import { config } from "../config/settings.flowa";
 
// Relative to execution directory
import { helpers } from "src/helpers.flowa";

Module Execution

Modules are executed once when first imported
Subsequent imports reuse the already-loaded module
Module code runs in isolated scope
Exports are cached for performance

Example

counter.flowa:

let count = 0;
 
export func increment() {
    count = count + 1;
    return count;
}
 
export func getCount() {
    return count;
}

main.flowa:

import { increment, getCount } from "counter.flowa";
 
print(increment());  // 1
print(increment());  // 2
print(getCount());   // 2

Best Practices

1. Use Clear Names

// Good
export func calculateTotal(items) { ... }
 
// Avoid
export func calc(x) { ... }

2. Group Related Exports

// math_utils.flowa
export func add(a, b) { return a + b; }
export func subtract(a, b) { return a - b; }
export func multiply(a, b) { return a * b; }

3. Avoid Circular Dependencies

Avoid having a.flowa import b.flowa which imports a.flowa.

4. Module Organization

project/
  ├── main.flowa
  ├── utils/
  │   ├── string.flowa
  │   └── array.flowa
  └── services/
      ├── auth.flowa
      └── database.flowa

Functions File System (fs)