Operator overloading framework classes?

General
1

Hello

I know that operator overloading is possible. But now I want to do operator overloading on existing framework classes, is that possible?
Eg: I want to concatenate a literal string and a folderitem. But I don’t want to type .Nativepath everywhere. So I want to do this:

Dim example As String

example = "teststring" + myAwesomeFolderItem[/code]

The errormessage I receive is: [quote]Type TextLiteral has no definition of 'Operator_Add' with type FolderItem[/quote] (something like that)

How can I accomplish this? I know I could subclass FolderItem and do an 'Operator_AddRight'. But I'm looking for a way without subclassing and use the build in classes of Xojo. I was thinking about Extending, but I have no idea how I could do an extends with operator overloading.

I tried this:

[code]Public Function Operator_AddRight(Extends fi As FolderItem, leftside As String) as String
  Return leftside + fi.NativePath
End Function

But that doesn’t work.

Thank you!

2

Operator overload methods must be class methods; they can’t use the Extends syntax. I’m not sure it’s possible to do what you’re asking.

3

You could subclass folderitem and add your method there.

4

If you do this you may also want to add operator_convert(f as folderitem) and operator_convert() as folderitem to make it easy to deal with all the framework functions that take & return folderitems

So something like

   dim f as FolderItem = SpecialFolder.DesktopFolder

can just turn into

   dim f as MyFolderItem = SpecialFolder.DesktopFolder

and not cause you piles of extra work

ie

Class MyFolderitem
  Public Function Operator_AddRight(leftside As String) as String
    Return leftside + fi.NativePath
  End Function

  Public Function Operator_convert() as folderitem
    return fi
  End Function

  Public Sub Operator_convert(f as folderitem)
    fi = f
  End Sub

  private fi as folderitem
End Class

makes code like

  Dim example As String
  Dim c As Class1 = SpecialFolder.Desktop

  example = "teststring" + c

still work reasonably simply

BUT with this approach I wont be surprised if you run into other impediments