# init(_:as:transform:) Creates a capture for the given component using the specified reference, attempting to transform with the given closure. ``` init(_ component: some RegexComponent, as reference: Reference, transform: @escaping (W) throws -> NewCapture?) where Output == (Substring, NewCapture, C1, C2, C3, C4, C5, C6) ``` ## Parameters `component` The regex component to capture. `reference` The reference to use for anything captured by `component`. `transform` A closure that takes the substring matched by `component` and returns a new value to capture, or `nil` if matching should proceed, backtracking if allowed. If `transform` throws an error, matching is abandoned and the error is returned to the caller. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)