NonEmpty and remove() functionality.

[nashysolutions]

The NonEmpty library is great.

I want to efficiently remove items from a NonEmpty collection, but I'm not sure what the best strategy is. In the following example, I'm using IdentifiedArray.

Is this the de-facto approach?

struct Standup: Equatable, Identifiable, Codable {
    
    typealias AttendeesArray = IdentifiedArrayOf<Attendee>
    typealias MeetingsArray = IdentifiedArrayOf<Meeting>
    
    let id: Tagged<Self, UUID>
    var attendees: NonEmpty<AttendeesArray> = .init(Attendee())
    var meetings: NonEmpty<MeetingsArray> = .init(Meeting())
}

extension Standup {
    
    mutating func deleteAttendees(atOffsets indicies: IndexSet) {
        let toKeep = attendees.elements.filterNotMatching(offsets: indicies)
        attendees = NonEmpty(toKeep) ?? .init(Attendee())
    }
}

extension IdentifiedArray where Element: Identifiable & Equatable {
    
    func filterNotMatching(offsets indicies: IndexSet) -> IdentifiedArrayOf<Element> {
        let toKeep = elements.filterNotMatching(offsets: indicies)
        return IdentifiedArrayOf(uniqueElements: toKeep)
    }
}

extension Collection where Element: Equatable {
    
    func filterNotMatching(offsets indicies: IndexSet) -> [Element] {
        enumerated().filter {
            !indicies.contains($0.offset)
        }.map { $0.element }
    }
}

Or this

extension Standup {
    
    mutating func deleteAttendees(atOffsets indicies: IndexSet) {
        var elements = attendees.elements
        for index in indicies {
            elements.remove(at: index)
        }
        attendees = NonEmpty(elements) ?? .init(Attendee())
    }
}

Ideally, would want a more generic approach, with perhaps a default value, to guarantee the collection won't be empty.

Is this cool?

extension NonEmpty where Collection == IdentifiedArrayOf<Attendee> {
    
    func excludingItems(atOffsets indicies: IndexSet) -> Self {
        var elements = self.elements
        for index in indicies {
            elements.remove(at: index)
        }
        return NonEmpty(elements) ?? .init(Attendee())
    }
}

[nashysolutions]

Would appreciate input from the community on this one.