The monadic or dyadic system function ŒINSTANCES returns a vector of references to all the instances of a given internal class. The right argument is either a class reference, or a character vector containing the name of an internal class.
If the left argument is omitted, or is 0, the list will include instances of the specified class and of any descendants of the class. If the left argument is 1, the list will be restricted to instances of the specified class itself only.
In this example, classes Rectangle and Triangle both inherit from class Polygon:
)CLASSES Polygon Rectangle Triangle T1„ŒNEW 'Triangle' ª T1.ŒDF 'Triangle1' T2„ŒNEW 'Triangle' ª T2.ŒDF 'Triangle2' P1„ŒNEW 'Polygon' ª P1.ŒDF 'Polygon1' R1„ŒNEW 'Rectangle' ª R1.ŒDF 'Rectangle1' ŒINSTANCES 'Polygon' © Form using class name as right arg Triangle1 Triangle2 Polygon1 Rectangle1 0 ŒINSTANCES Polygon © Form using class reference as right arg Triangle1 Triangle2 Polygon1 Rectangle1 1 ŒINSTANCES Polygon Polygon1
ŒINSTANCES cannot be used to find instances of external classes.