When working with 4D, you might come across a compiler warning that states: "Assumes that the pointer points to an alphanumeric expression. (533.1)." This warning indicates that the compiler cannot automatically infer the type, so it warns you that if it is not a text at Runtime. Take for example this little code:

var $folder : 4D.Folder:=Folder("/PACKAGE/") $path:=$folder.platformPath $del:=$folder.platformPath[[Length($path)]]

We can get rid of the warning by adding String() command:

var $del:=String($folder.platformPath)[[Length($path)]] // String() will make the warning disappear

By converting the value to a string explicitly, you eliminate the compiler warning and ensure your code behaves as expected.