I wish this helpful for you This is a known limitation of GHC’s implementation of visible type application. Specifically, Proxy is sometimes still necessary in order to allow the argument to a higher-rank function (such as your toto function) to access a type variable. There is a GHC proposal to add a solution to this problem, in the form of type variable bindings in lambda-expressions. Using the syntax from the proposal, your toto function could be written as
To fix the issue you can do It really depends what you want to do; but ultimately common data-binding (for simple properties, done manually) consists of: obtaining a property; preferably via TypeDescriptor.GetProperties(obj)[propName], giving you an abstraction (PropertyDescriptor) asking the property if it is read-only (.IsReadOnly) obtain (or set) the value (.GetValue(), .SetValue()) asking it for a converter to format / parse the value (.Converter, .ConvertFromString(), .ConvertToString()) THIS is a key bit that means you don't have to worry about what the data type is asking it for the caption (.DisplayName, or .Name if that it empty/null) asking it if it supports property-specific notification (.SupportsChangeEvents) asking it to add/remove a change handler (.AddValueChanged(), .RemoveValueChanged()) you might also want to look at whether the object supports centralised notification (look for INotifyPropertyChanged)
Hope that helps I figured out the problem. The thing is that TabView shows this error even if there is some error in the closure. So the code of creating the TabView is correct but the problem is the way I'm initialising DataGridPage. I changed the name of the property type to data inside DataGridPage but here I'm still using type property. I fixed it and it stopped showing me the warning. I think SwiftUI is a new framework and it has still a lot improvement to do in terms of debugging. I hope it will mature in future and we would be able to pin point the exact error instead of this vague statement.