Cut a sequence given a predicate taking in successive elements

Cut.swift

extension Collection where SubSequence: Sequence, SubSequence.Iterator.Element == Iterator.Element {
    func cut(atSuccession shouldCut: (Iterator.Element, Iterator.Element) throws -> Bool) rethrows -> [Self.SubSequence] {
        var (fromIndex, toIndex) = (startIndex, startIndex)
        var result: [SubSequence] = []
        for (x, y) in zip(self, dropFirst()) {
            defer { toIndex = index(after: toIndex) }
            guard try shouldCut(x, y) else { continue }
            result.append(self[fromIndex...toIndex])
            fromIndex = index(after: toIndex)
        }
        result.append(self[fromIndex...toIndex])
        return result
    }
}

// Example
// print([1, 2, 3, 4, 3, 2, 8, 9, 10, 9, 4, 3, 2].cut(atSuccession: { abs($0 - $1) > 1 }))
// -> [ArraySlice([1, 2, 3, 4, 3, 2]), ArraySlice([8, 9, 10, 9]), ArraySlice([4, 3, 2])]