⎕RECLASS Change class of objects

The dyadic system function ⎕RECLASS allows you to change the class of one or more object instances, provided these are user-defined APL objects.

The left argument should be either a single class reference, or a class name as a character vector. The right argument should be an array of object instances to be converted to the class specified in the left argument.

If the instances being reclassified contain non-default property values, these will be deleted unless they are also valid in the new class.

The main occasion when ⎕RECLASS is useful is if you have modified the class hierarchy. For example, you might have a class Car which inherits from Vehicle. You now decide you would like to create new classes SportsCar and FamilyCar, and change the class of your existing Car objects. To do this, you can use ⎕INSTANCES to find all instances of Car in the workspace, and change their class according to some criterion which you set:

      AllCars ← 1 ⎕INSTANCES Car
      AllCars.TopSpeed
130 135 143 120 91 141 117 123 98 84 135 155 111 122
      SportsCar ⎕RECLASS ((AllCars.TopSpeed) > 140)/AllCars
      FamilyCar ⎕RECLASS ((AllCars.TopSpeed) ≤ 140)/AllCars
      AllCars
[FamilyCar] [FamilyCar] [SportsCar] [FamilyCar] [FamilyCar] [SportsCar]
      [FamilyCar] [FamilyCar] [FamilyCar] [FamilyCar] [FamilyCar] [SportsCar]
      [FamilyCar] [FamilyCar]