Signature: padStart(s: string, targetLength: int, fill: string) -> Result<string, StringError>

Description: Pads s on the left with copies of fill to reach targetLength bytes.

Parameters

• s (string): The string to pad
• targetLength (int): Desired total length
• fill (string): Padding string (non-empty)

Returns: Result<string, StringError>

Example

padStart("7", 3, "0")  // Success { value: "007" }