Move interface logic to interface.py

magma/circuit.py

@@ -56,12 +56,8 @@ def _add_port(defn, name, typ):
     if name in defn.IO.ports or name in defn.interface.ports:
         raise ValueError(f"{name} already is a port of {defn.name}")
     defn.IO.ports.update({name: typ})
-    ifc = DeclareInterface(name, typ)
-    ifc_inst = ifc(defn=defn, renamed_ports={})
-    defn.interface.ports.update(ifc_inst.ports)
-    type(defn.interface).Decl += (name, typ)
-    for name, port in ifc_inst.ports.items():
-        setattr(defn, name, port)
+    defn.interface.add_port(name, typ, defn=defn)
+    setattr(defn, name, defn.interface.ports[name])
 
 
 #

magma/interface.py

@@ -193,31 +193,40 @@ def __str__(self):
 #
 #  interface = Interface()
 #
-class _DeclareInterface(_Interface):
-    def __init__(self, renamed_ports={}, inst=None, defn=None):
 
-        # parse the class Interface declaration
-        names, ports = parse(self.Decl)
 
-        args = OrderedDict()
+def _get_port(name, port, renamed_ports, inst, defn):
+    if   inst: ref = InstRef(inst, name)
+    elif defn: ref = DefnRef(defn, name)
+    else:      ref = AnonRef(name)
 
-        for name, port in zip(names, ports):
-            if   inst: ref = InstRef(inst, name)
-            elif defn: ref = DefnRef(defn, name)
-            else:      ref = AnonRef(name)
+    if hasattr(port, "origPortName"):
+        ref.name = port.origPortName
+    if name in renamed_ports:
+        ref.name = renamed_ports[name]
 
-            if hasattr(port, "origPortName"):
-                ref.name = port.origPortName
-            if name in renamed_ports:
-                ref.name = renamed_ports[name]
+    if defn:
+        port = port.flip()
 
-            if defn:
-               port = port.flip()
+    return port(name=ref)
 
-            args[name] = port(name=ref)
 
+class _DeclareInterface(_Interface):
+    def __init__(self, renamed_ports={}, inst=None, defn=None):
+        # Parse the class Interface declaration.
+        names, ports = parse(self.Decl)
+        args = OrderedDict()
+        for name, port in zip(names, ports):
+            args[name] = _get_port(name, port, renamed_ports, inst, defn)
         self.ports = args
 
+    def add_port(self, name, typ, renamed_ports={}, inst=None, defn=None):
+        assert name not in self.Decl and name not in self.ports
+        port = _get_port(name, typ, renamed_ports, inst, defn)
+        self.ports.update({name: port})
+        type(self).Decl += (name, typ)
+
+
 class InterfaceKind(Kind):
     def __init__(cls, *args, **kwargs):
         super().__init__(*args, **kwargs)