If check producing "Compiler is unable to type-check this expression in reasonable time error&q-CodePudding

The

Working screenshot below when if statement is commented out

CodePudding user response：

You need to break your view up a little to help the type checker out.

Ideally what you should do is create a set of View structs so you don't have the pyramid of doom you have at the moment.

But, in the meantime, what you can do is simply move a coherent chunk of code out into a separate method, tag it as a ViewBuilder, and you should be able to find a refactoring that works.

I'd do something like this:

var body: some View { ZStack{ VStack { HStack { ScrollView(.vertical, showsIndicators: false) { //iterate on consumers (will be one since only one user signs in) ForEach(self.consumer.datas) { user in //iterate on available books ForEach(self.books.datas) { books in userView(user, books) }//ForEach books }//ForEach users (only accessing one user account) }//ScrollView }//HStack }//VStack }//ZStack //onAppear is used to load up to date information from Firebase .onAppear{ self.consumer.retrieveData() self.books.retrieveData() } } @ViewBuilder func userView(_ user: userInfo, _ books: books_Data) -> some View { VStack { ForEach(user.loved, id: \.self) { item in // //if the current book was liked by the user, do the following if(books.id == item){ VStack { Button(action: { self.book_detail = books // }) { if let url = URL(string: books.largeImg) { AnimatedImage(url: url) .resizable() .frame(width: 60, height: 90) .clipped() .cornerRadius(8) .overlay( RoundedRectangle(cornerRadius: 8) .stroke(Color(white: 0.4)) ) .shadow(radius: 3) } } } } }//ForEach }//VStack }

As far as I know – I am not an expert on the inner workings of the type inference engine – how this works is that when the type checker sees the userView(user, books), because we've told it it will produce a view, it can stop there and then it separately checks the types for the body of the ViewBuilder itself.

I think your intuition is correct, I have found that if statements within SwiftUI code really gives the type checker a hard time.