Generate IndexPaths from Sectioned DataSource

SectionProviderProtocol.swift

protocol SectionProviderProtocol {
    associatedtype T
    var header: String? { get }
    var rows: [T] { get }
}

extension Array where Element: SectionProviderProtocol, Element.T: Equatable {
    var indexPaths: [IndexPath] {
        var paths: [IndexPath] = []
        for (section, item) in self.enumerated() {
            let ips = (0..<item.rows.count).map({IndexPath(row: $0, section: section)})
            paths.append(contentsOf: ips)
        }
        return paths
    }
    
    func indexPaths<T>(from another: Array<T>) -> [IndexPath] where T == Element.T {
        var paths = [IndexPath]()
        for (section, item) in self.enumerated() {
            if let index = item.rows.indices(from: another) {
                let idx = index.compactMap({IndexPath(row: $0, section: section)})
                paths.append(contentsOf: idx)
            }
        }
        return paths
    }
    
}

extension Array where Element: Equatable {
    func indices(from another: Array) -> [Int]? {
        guard !another.isEmpty else { return nil }
        var idx: [Int] = []
        for element in another {
            if let index = self.index(of: element) {
                idx.append(index)
            }
        }
        return idx.isEmpty ? nil : idx
    }
}