# startsWith

Check if the current state of a RefString starts with a substring.

## Signatures

```ts
export declare const startsWith: {
    (searchString: string, position?: number): <E, R>(ref: RefString<E, R>) => RefSubject.Computed<boolean, E, R>;
    <E, R>(ref: RefString<E, R>, searchString: string, position?: number): RefSubject.Computed<boolean, E, R>;
};
```

## Why

Check if the current state of a RefString starts with a substring. The operation remains
attached to the RefSubject's versioned state boundary.

## Ownership and lifetime

The starts with view retains no independent state. An Effect read samples the source once; Fx
observation follows later pushes and its observing Scope owns subscription cleanup.