Your First Macro

Let's create a class that uses Macroforge's derive macros to automatically generate useful methods.

Creating a Class with Derive Macros

Start by creating a simple User class. We'll use the @derive decorator to automatically generate methods.

Before (Your Code)

/** @derive(Debug, Clone, PartialEq) */
export class User {
    name: string;
    age: number;
    email: string;

    constructor(name: string, age: number, email: string) {
        this.name = name;
        this.age = age;
        this.email = email;
    }
}

After (Generated)

export class User {
    name: string;
    age: number;
    email: string;

    constructor(name: string, age: number, email: string) {
        this.name = name;
        this.age = age;
        this.email = email;
    }

    static toString(value: User): string {
        return userToString(value);
    }

    static clone(value: User): User {
        return userClone(value);
    }

    static equals(a: User, b: User): boolean {
        return userEquals(a, b);
    }
}

export function userToString(value: User): string {
    const parts: string[] = [];
    parts.push('name: ' + value.name);
    parts.push('age: ' + value.age);
    parts.push('email: ' + value.email);
    return 'User { ' + parts.join(', ') + ' }';
}

export function userClone(value: User): User {
    const cloned = Object.create(Object.getPrototypeOf(value));
    cloned.name = value.name;
    cloned.age = value.age;
    cloned.email = value.email;
    return cloned;
}

export function userEquals(a: User, b: User): boolean {
    if (a === b) return true;
    return a.name === b.name && a.age === b.age && a.email === b.email;
}

Using the Generated Methods

TypeScript

const user = new User("Alice", 30, "[email protected]");

// Debug: toString()
console.log(user.toString());
// Output: User { name: Alice, age: 30, email: [email protected] }

// Clone: clone()
const copy = user.clone();
console.log(copy.name); // "Alice"

// Eq: equals()
console.log(user.equals(copy)); // true

const different = new User("Bob", 25, "[email protected]");
console.log(user.equals(different)); // false

Customizing Behavior

You can customize how macros work using field-level decorators. For example, with the Debug macro: