from myhdl import *

class Interface():

    def __init__(self):
        self.data = Signal(False)

class HDLClass1(object):

    @block
    def model(self, clock, input_interface, output_interface):

        internal_in = Interface()
        internal_out = Interface()

        @always_comb
        def assignments():
            internal_in.data.next = input_interface.data
            output_interface.data.next = internal_out.data

        @always(clock.posedge)
        def do_something():
            internal_out.data.next = internal_in.data.next

        return do_something, assignments

class HDLClass2(HDLClass1):
    pass

class Pipeline(object):

    def __init__(self):

        self.class1_inst = HDLClass1()
        self.class2_inst = HDLClass2()

    @block
    def pipeline_hdl(
        self, clock, input_interface, output_interface):

        intermediate_interface = Interface()

        class1_hdl_inst = self.class1_inst.model(
            clock, input_interface, intermediate_interface)

        class2_hdl_inst = self.class2_inst.model(
            clock, intermediate_interface, output_interface)

        return class1_hdl_inst, class2_hdl_inst

def build_it():
    pipeline = Pipeline()

    clock = Signal(False)
    reset = Signal(False)
    input_interface = Interface()
    output_interface = Interface()

    inst = pipeline.pipeline_hdl(clock, input_interface, output_interface)
    inst.convert()

if __name__ == '__main__':
    build_it()