Function Once

Once<T>(): Once<T>

Creates a new empty Once<T>.

Type Parameters

T
The type of value to store.

Returns Once<T>

A new uninitialized Once.

Example

// Basic usage
const once = Once<string>();
once.set('hello');
console.log(once.get().unwrap()); // 'hello'

Example

// Sync lazy singleton pattern
const logger = Once<Logger>();

function getLogger(): Logger {
    return logger.getOrInit(() => new Logger('app'));
}

Example

// Fallible sync initialization
const config = Once<Config>();

function loadConfig(): Result<Config, Error> {
    return config.getOrTryInit(() => {
        const data = readFileSync('config.json');
        return data ? Ok(JSON.parse(data)) : Err(new Error('Config not found'));
    });
}