feat(hugr-py): add alias, make deserialize abstract

all ops covered!

hugr-py/src/hugr/_function.py

@@ -8,7 +8,7 @@
 from ._dfg import _DfBase
 from hugr._node_port import Node
 from ._hugr import Hugr
-from ._tys import TypeRow, TypeParam, PolyFuncType
+from ._tys import TypeRow, TypeParam, PolyFuncType, Type, TypeBound
 
 
 @dataclass
@@ -47,3 +47,9 @@ def declare_function(self, name: str, signature: PolyFuncType) -> Node:
 
     def add_const(self, value: val.Value) -> Node:
         return self.hugr.add_node(ops.Const(value), self.hugr.root)
+
+    def add_alias_defn(self, name: str, ty: Type) -> Node:
+        return self.hugr.add_node(ops.AliasDefn(name, ty), self.hugr.root)
+
+    def add_alias_decl(self, name: str, bound: TypeBound) -> Node:
+        return self.hugr.add_node(ops.AliasDecl(name, bound), self.hugr.root)

hugr-py/src/hugr/_ops.py

@@ -771,3 +771,37 @@ def outer_signature(self) -> tys.FunctionType:
 
     def set_in_types(self, types: tys.TypeRow) -> None:
         self._type_row = types
+
+
+@dataclass
+class AliasDecl(Op):
+    name: str
+    bound: tys.TypeBound
+    num_out: int | None = 0
+
+    def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> sops.AliasDecl:
+        return sops.AliasDecl(
+            parent=parent.idx,
+            name=self.name,
+            bound=self.bound,
+        )
+
+    def port_kind(self, port: InPort | OutPort) -> tys.Kind:
+        raise InvalidPort(port)
+
+
+@dataclass
+class AliasDefn(Op):
+    name: str
+    definition: tys.Type
+    num_out: int | None = 0
+
+    def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> sops.AliasDefn:
+        return sops.AliasDefn(
+            parent=parent.idx,
+            name=self.name,
+            definition=self.definition.to_serial_root(),
+        )
+
+    def port_kind(self, port: InPort | OutPort) -> tys.Kind:
+        raise InvalidPort(port)

hugr-py/src/hugr/serialization/ops.py

@@ -43,9 +43,9 @@ def display_name(self) -> str:
         """Name of the op for visualisation"""
         return self.__class__.__name__
 
+    @abstractmethod
     def deserialize(self) -> _ops.Op:
         """Deserializes the model into the corresponding Op."""
-        raise NotImplementedError
 
 
 # ----------------------------------------------------------
@@ -602,12 +602,18 @@ class AliasDecl(BaseOp):
     name: str
     bound: TypeBound
 
+    def deserialize(self) -> _ops.AliasDecl:
+        return _ops.AliasDecl(self.name, self.bound)
+
 
 class AliasDefn(BaseOp):
     op: Literal["AliasDefn"] = "AliasDefn"
     name: str
     definition: Type
 
+    def deserialize(self) -> _ops.AliasDefn:
+        return _ops.AliasDefn(self.name, self.definition.deserialize())
+
 
 class OpType(RootModel):
     """A constant operation."""

hugr-py/tests/test_hugr_build.py

@@ -389,3 +389,11 @@ def test_lift() -> None:
     lift = d.add(ops.Lift("X")(q))
     d.set_outputs(lift)
     _validate(d.hugr)
+
+
+def test_alias() -> None:
+    mod = Module()
+    _dfn = mod.add_alias_defn("my_int", INT_T)
+    _dcl = mod.add_alias_decl("my_bool", tys.TypeBound.Eq)
+
+    _validate(mod.hugr)