A programming environment may have an abstract interface definition that may contain a redirection definition that may cause a call to be bound to a redirected method or function. The redirected method or function may be a conditional redirection, and some embodiments may perform various checks including signature checks, static and runtime access checks, and other verifications for the redirected method. The redirection may enable a programmer to modify a portion of an interface without having to re-implement all of the functions of the interface.