oldTableDataSource.swift

final class OldTableDataSource: NSObject {
}

private extension OldTableDataSource {
    enum Section: Int {
        case Header, Body, Footer

        static let numberOfSections = 3

        enum HeaderRows: Int {
            case Row1, Row2

            static let numberOfRows = 2
        }

        enum BodyRows: Int {
            case row1, row2, row3, row4

            static let numberOfRows = 4
        }

        enum FooterRows: Int {
            case row1, row2, row3, row4

            static let numberOfRows = 4
        }
    }

    // Because I'm not exhaustively covering the cases, I'm cheating with a generic
    func cellForRow<RowType>(row: RowType) -> UITableViewCell {
        return UITableViewCell()
    }

}

extension OldTableDataSource: UITableViewDataSource {

    func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        return Section.numberOfSections
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        guard let section = Section(rawValue: section) else {
            fatalError()
        }
        switch section {
        case .Header: return Section.HeaderRows.numberOfRows
        case .Body: return Section.BodyRows.numberOfRows
        case .Footer: return Section.FooterRows.numberOfRows
        }
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        guard let section = Section(rawValue: indexPath.section) else {
            fatalError()
        }
        let cell: UITableViewCell
        switch section {
        case .Header:
            guard let row = Section.HeaderRows.init(rawValue: indexPath.row) else {
                fatalError()
            }
            cell = cellForRow(row)
        case .Body:
            guard let row = Section.BodyRows.init(rawValue: indexPath.row) else {
                fatalError()
            }
            cell = cellForRow(row)
        case .Footer:
            guard let row = Section.FooterRows.init(rawValue: indexPath.row) else {
                fatalError()
            }
            cell = cellForRow(row)
        }
        return cell
    }
}