# Brand

The Brand module provides type-safe branding for values, allowing you to create distinct types from primitive values without runtime overhead.

## Brand

Creates a branded type that wraps a value with a unique brand identifier.

```typescript
import { Brand } from 'funkcia/brand';

type UserId = Brand<string, 'UserId'>;
type ProductId = Brand<string, 'ProductId'>;

const userId ='user_123' as UserId;
const productId = 'product_456' as ProductId;

declare function getUser(id: UserId): User | null;

getUser(userId); // OK
getUser(productId); // Type error: ProductId is not assignable to UserId
```

### Brand.of

Creates a brand constructor. Can be used with or without validation.

#### Without validation

```typescript
import { Brand } from 'funkcia/brand';

type Email = Brand<string, 'Email'>;

const Email = Brand.of<Email>();

const email: Email = Email('user@example.com');
```

#### With validation

Creates a brand parser with validation and error handling.

```typescript
import { Brand, Result } from 'funkcia/brand';

type Email = Brand<string, 'Email'>;

const Email = Brand.of<Email, InvalidEmailError>(
  (value) => value.includes('@'),
  (value) => new InvalidEmailError(value),
);

// Throws if validation fails
const email: Email = Email.parse('user@example.com');

// Returns Result instead of throwing
const result = Email.safeParse('invalid');
// Result<Email, InvalidEmailError>


const value: string = 'user@example.com';

// Type guard
if (Email.is(value)) {
  // value is Email
}
```

### Brand.unbrand

Removes the brand from a branded value, returning the underlying type.

```typescript
import { Brand } from 'funkcia/brand';

type UserId = Brand<string, 'UserId'>;

const userId = 'user_123' as UserId;

const unbranded: string = Brand.unbrand(userId);
```

### Brand types

#### Brand.Unbrand

Utility type that extracts the underlying type from a branded type.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://funkcia.lukemorales.io/modules/brand.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.