'SwiftUI Table error: The compiler is unable to type-check this expression in reasonable time

I have a very strange situation happening in my code (SwiftUI, macOS app), which doesn't make sense to me. The following builds and runs as expected:

private var bodySongs: some View {
    Table(musicLibraryProvider.filtered(by: searchTerm), selection: $selectedSongID) {
//            TableColumn("") {
//                Image(nsImage: $0.artwork?.image ?? NSImage(named: "EmptyAlbum")!)
//                    .resizable()
//                    .aspectRatio(contentMode: .fit)
//                    .frame(width: 22.5, height: 22.5)
//                    .clipShape(RoundedRectangle(cornerRadius: 2))
//                    .overlay(RoundedRectangle(cornerRadius: 2).stroke(Color.gray, lineWidth: 0.5))
//            }.width(22.5)
        TableColumn("Title") {
            Text($0.title)
        }
        TableColumn("Artist") {
            Text($0.artist?.name ?? "")
        }
        TableColumn("Album") {
            Text($0.album.title ?? "")
        }
        TableColumn("Year") {
            Text("\($0.year)")
        }
    }
    .navigationTitle("Songs")
}

If I uncomment the image column, it throws this error when compiling:

The compiler is unable to type-check this expression in reasonable time; try breaking up the expression into distinct sub-expressions

But if I comment out the next two columns, it compiles and runs:

private var bodySongs: some View {
    Table(musicLibraryProvider.filtered(by: searchTerm), selection: $selectedSongID) {
        TableColumn("") {
            Image(nsImage: $0.artwork?.image ?? NSImage(named: "EmptyAlbum")!)
                .resizable()
                .aspectRatio(contentMode: .fit)
                .frame(width: 22.5, height: 22.5)
                .clipShape(RoundedRectangle(cornerRadius: 2))
                .overlay(RoundedRectangle(cornerRadius: 2).stroke(Color.gray, lineWidth: 0.5))
        }.width(22.5)
//            TableColumn("Title") {
//                Text($0.title)
//            }
//            TableColumn("Artist") {
//                Text($0.artist?.name ?? "")
//            }
        TableColumn("Album") {
            Text($0.album.title ?? "")
        }
        TableColumn("Year") {
            Text("\($0.year)")
        }
    }
    .navigationTitle("Songs")
}

In other words, these three columns cannot exist at the same time. Does anyone knows why?

macosswiftui


Solution 1:[1]

It's best not to do any computation inside body because it has to run as fast as possible for SwiftUI to work correctly. You can resolve this by just reading from a property that already has the data in a filtered state.

You can use one of the side-effect modifiers to achieve this, like onAppear, onChange or even .task(id:searchTerm) if you'd like to do the work of using the current search term to update an @State var with the filtered results asynchronously.

Sources

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Source: Stack Overflow

Solution Source
Solution 1 malhal

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