Class virtual Cf_machine.substate

class virtual [['a, 'b]] substate : object .. end

A virtual class to represent the public interface of object-oriented gadget states. Use inherit ['i, 'o] substate or

constrain 'self = ('i, 'o)
    #substate

to derive a class that implements part of a state in a machine.

method virtual next : (< next : 'c; .. >, 'a, 'b, unit) Cf_gadget.t as 'c

Use obj#next to transition the state of the machine to obj.