macOS で SwiftUI の Table に数千件のデータと sortOrder を放り込むとハングするのを回避する。

nonisolated
public init<Data, Sort>(
  _ data: Data,
  selection: Binding<Set<Value.ID>>,
  sortOrder: Binding<[Sort]>,
  @TableColumnBuilder<Value, Sort> columns: () -> Columns
) where Rows == TableForEachContent<Data>, Data : RandomAccessCollection, Sort : SortComparator, Columns.TableRowValue == Data.Element, Data.Element == Sort.Compared

import SwiftUI

private struct TableItem: Codable, Equatable, Comparable, Hashable, Identifiable, Sendable {
    let name: String
    let starCount: Int
    let rank: Int
    let uuid: UUID

    var id: UUID { uuid }

    static func < (lhs: Self, rhs: Self) -> Bool {
        lhs.rank < rhs.rank
    }
}

private func createRandomName() -> String {
    let names = ["Alice", "Bob", "Charlie", "David", "Eve", "Frank", "Grace", "Heidi", "Ivan", "Judy"]
    while let choice = names.randomElement() {
        while let choice2 = names.randomElement(), choice != choice2 {
            while let choice3 = names.randomElement(), choice != choice3, choice2 != choice3 {
                return "\(choice)-\(choice2)-\(choice3)"
            }
        }
    }
    fatalError("This should never happen")
}

private func createRandomTableItems(count: Int) -> [TableItem] {
    (0..<count).map { _ in
        TableItem(name: createRandomName(), starCount: Int.random(in: 0..<5), rank: Int.random(in: 0..<10000), uuid: UUID())
    }
}

@main
struct BrokenSwiftUITableApp: App {

    // NOTE: 後述する .id(sortOrder) を追加しない場合、 16 GB RAM の M1 Mac mini では 4000 件を越えたあたりでレインボーカーソルで死ぬ。
    private let items: [TableItem] = createRandomTableItems(count: 10000)

    private var sortedItems: [TableItem] {
        items.sorted(using: sortOrder)
    }

    @State private var selection: Set<TableItem.ID> = []

    @State private var sortOrder = [
        KeyPathComparator(\TableItem.rank, order: .reverse),
        KeyPathComparator(\TableItem.name, order: .forward),
    ]

    @State private var sortId = UUID()

    var body: some Scene {
        WindowGroup {
            Table(sortedItems, selection: $selection, sortOrder: $sortOrder) {
                TableColumn("Rank", value: \.rank) { item in
                    Text("\(item.rank)")
                        .monospacedDigit()
                }

                TableColumn("Star", value: \.starCount) { item in
                    Text(String(repeating: "⭐️", count: item.starCount))
                        .monospacedDigit()
                }

                TableColumn("Name", value: \.name) { item in
                    Text(item.name)
                        .monospaced()
                }

                TableColumn("UUID", value: \.uuid) { item in
                    Text(item.uuid.uuidString)
                        .monospaced()
                        .foregroundStyle(.secondary)
                }
            }
            // .id(sortOrder) // NOTE: これを付ければ sortOrder 毎に Table が作り直されるので問題が起きなくなる。
        }
    }
}

@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, *)
extension View {
    /// Binds a view's identity to the given proxy value.
    ///
    /// When the proxy value specified by the `id` parameter changes, the
    /// identity of the view — for example, its state — is reset.
    @inlinable nonisolated public func id<ID>(_ id: ID) -> some View where ID : Hashable
}