Refactoring py/ports (#131)

* - refactor creation of ImplicitVarPort into a common function

* - refactor creation of ImplicitVarPort into a common function

* - refactor inheritage of PyInPort and PyOutPort to a common parent class and removed anonymous argument list for their init functions

* - Adressed requested changes of PR (rename of class, adding comments)

* - fix unit tests
- try resolving conflict

* - Adressed requested changes of PR (adding comments)

src/lava/magma/compiler/builders/builder.py

@@ -29,7 +29,7 @@
 from lava.magma.compiler.utils import VarInitializer, PortInitializer, \
     VarPortInitializer
 from lava.magma.core.model.py.ports import (
-    AbstractPyPort,
+    AbstractPyIOPort,
     PyInPort,
     PyOutPort,
     PyRefPort,
@@ -340,7 +340,7 @@ def build(self):
         for name, p in self.py_ports.items():
             # Build PyPort
             lt = self._get_lava_type(name)
-            port_cls = ty.cast(ty.Type[AbstractPyPort], lt.cls)
+            port_cls = ty.cast(ty.Type[AbstractPyIOPort], lt.cls)
             csp_ports = []
             if name in self.csp_ports:
                 csp_ports = self.csp_ports[name]

src/lava/magma/compiler/compiler.py

@@ -34,7 +34,7 @@
 from lava.magma.core.model.py.ports import RefVarTypeMapping
 from lava.magma.core.model.sub.model import AbstractSubProcessModel
 from lava.magma.core.process.ports.ports import AbstractPort, VarPort, \
-    ImplicitVarPort
+    ImplicitVarPort, RefPort
 from lava.magma.core.process.process import AbstractProcess
 from lava.magma.core.resources import CPU, NeuroCore
 from lava.magma.core.run_configs import RunConfig
@@ -217,21 +217,10 @@ def _propagate_var_ports(proc: AbstractProcess):
         for vp in proc.var_ports:
             v = vp.var.aliased_var
             if v is not None:
-                sub_proc = v.process
                 # Create an implicit Var port in the sub process
-                new_vp = ImplicitVarPort(v)
-                # Propagate name and parent process of Var to VarPort
-                new_vp.name = "_" + v.name + "_implicit_port"
-                new_vp.process = sub_proc
-                # VarPort name could shadow existing attribute
-                if hasattr(sub_proc, new_vp.name):
-                    raise AssertionError(
-                        "Name of implicit VarPort might conflict"
-                        " with existing attribute.")
-                setattr(sub_proc, new_vp.name, new_vp)
-                sub_proc.var_ports.add_members({new_vp.name: new_vp})
+                imp_vp = RefPort.create_implicit_var_port(v)
                 # Connect the VarPort to the new VarPort
-                vp.connect(new_vp)
+                vp.connect(imp_vp)
 
     def _expand_sub_proc_model(self,
                                model_cls: ty.Type[AbstractSubProcessModel],