Getting the range of a regex capture

Using Swift
1

With a regex match match, I know I can get the range of the entire match with match.range.

If there is a capture group (say at index 1), I can get the range of the capture group with:

let range = match.1.output.startIndex..< match.1.output.endIndex.

Is there a less verbose way to get the range of a capture group?

2

Unfortunately not. But I have used this extension on Collection to get it.

extension Collection {
    var indexRange: Range<Index> {
        startIndex..<endIndex
    }
}

Then Substring gets this, too, and match.1.output.indexRange gets you want you want.

1 Like
3

Thanks @jonathanpenn, also good to know I wasn't missing something.

4

Alternatively,

let range = Range(match.output.1.indices)

extension Range {
  init<Collection: Swift.Collection>(_ indices: DefaultIndices<Collection>)
  where Collection.Index == Bound {
    self = indices.startIndex..<indices.endIndex
  }
}
3 Likes