feat(hugr-py): define type hierarchy separate from serialized (#1176)

Closes #1172

Changes in first commit.
Note second commit is just running the schema update, which appears to
be trivial and non-breaking.

Coverage not great because this hierarchy is comprehensive (unlike the
Ops) but not all are tested. Deemed not worth adding a load of boiler
plate tests for now.

hugr-py/src/hugr/_dfg.py

@@ -5,7 +5,7 @@
 
 from ._ops import Op, Command, Input, Output, DFG
 from ._exceptions import NoSiblingAncestor
-from hugr.serialization.tys import FunctionType, Type
+from hugr._tys import FunctionType, Type
 
 
 @dataclass()

hugr-py/src/hugr/_hugr.py

@@ -19,9 +19,9 @@
 from typing_extensions import Self
 
 from hugr._ops import Op
+from hugr._tys import Type
 from hugr.serialization.ops import OpType as SerialOp
 from hugr.serialization.serial_hugr import SerialHugr
-from hugr.serialization.tys import Type
 from hugr.utils import BiMap
 
 from ._exceptions import ParentBeforeChild

hugr-py/src/hugr/_ops.py

@@ -4,7 +4,8 @@
 from typing import Generic, Protocol, TypeVar, TYPE_CHECKING
 from hugr.serialization.ops import BaseOp
 import hugr.serialization.ops as sops
-import hugr.serialization.tys as tys
+from hugr.utils import ser_it
+import hugr._tys as tys
 
 if TYPE_CHECKING:
     from hugr._hugr import Hugr, Node, Wire
@@ -43,25 +44,25 @@ def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> T:
 
 @dataclass()
 class Input(Op):
-    types: list[tys.Type]
+    types: tys.TypeRow
 
     @property
     def num_out(self) -> int | None:
         return len(self.types)
 
     def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> sops.Input:
-        return sops.Input(parent=parent.idx, types=self.types)
+        return sops.Input(parent=parent.idx, types=ser_it(self.types))
 
     def __call__(self) -> Command:
         return super().__call__()
 
 
 @dataclass()
 class Output(Op):
-    types: list[tys.Type]
+    types: tys.TypeRow
 
     def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> sops.Output:
-        return sops.Output(parent=parent.idx, types=self.types)
+        return sops.Output(parent=parent.idx, types=ser_it(self.types))
 
 
 @dataclass()
@@ -81,21 +82,21 @@ def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> sops.CustomOp:
             parent=parent.idx,
             extension=self.extension,
             op_name=self.op_name,
-            signature=self.signature,
+            signature=self.signature.to_serial(),
             description=self.description,
-            args=self.args,
+            args=ser_it(self.args),
         )
 
 
 @dataclass()
 class MakeTuple(Op):
-    types: list[tys.Type]
+    types: tys.TypeRow
     num_out: int | None = 1
 
     def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> sops.MakeTuple:
         return sops.MakeTuple(
             parent=parent.idx,
-            tys=self.types,
+            tys=ser_it(self.types),
         )
 
     def __call__(self, *elements: Wire) -> Command:
@@ -104,7 +105,7 @@ def __call__(self, *elements: Wire) -> Command:
 
 @dataclass()
 class UnpackTuple(Op):
-    types: list[tys.Type]
+    types: tys.TypeRow
 
     @property
     def num_out(self) -> int | None:
@@ -113,7 +114,7 @@ def num_out(self) -> int | None:
     def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> sops.UnpackTuple:
         return sops.UnpackTuple(
             parent=parent.idx,
-            tys=self.types,
+            tys=ser_it(self.types),
         )
 
     def __call__(self, tuple_: Wire) -> Command:
@@ -131,5 +132,5 @@ def num_out(self) -> int | None:
     def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> sops.DFG:
         return sops.DFG(
             parent=parent.idx,
-            signature=self.signature,
+            signature=self.signature.to_serial(),
         )

hugr-py/src/hugr/_tys.py

@@ -0,0 +1,271 @@
+from __future__ import annotations
+from dataclasses import dataclass, field
+import hugr.serialization.tys as stys
+from hugr.utils import ser_it
+from typing import Any, Protocol, runtime_checkable
+
+ExtensionId = stys.ExtensionId
+ExtensionSet = stys.ExtensionSet
+TypeBound = stys.TypeBound
+
+
+class TypeParam(Protocol):
+    """A type parameter."""
+
+    def to_serial(self) -> stys.BaseTypeParam: ...
+
+    def to_serial_root(self) -> stys.TypeParam:
+        return stys.TypeParam(root=self.to_serial())  # type: ignore[arg-type]
+
+
+class TypeArg(Protocol):
+    """A type argument."""
+
+    def to_serial(self) -> stys.BaseTypeArg: ...
+
+    def to_serial_root(self) -> stys.TypeArg:
+        return stys.TypeArg(root=self.to_serial())  # type: ignore[arg-type]
+
+
+@runtime_checkable
+class Type(Protocol):
+    """A type."""
+
+    def to_serial(self) -> stys.BaseType: ...
+
+    def to_serial_root(self) -> stys.Type:
+        return stys.Type(root=self.to_serial())  # type: ignore[arg-type]
+
+
+TypeRow = list[Type]
+
+# --------------------------------------------
+# --------------- TypeParam ------------------
+# --------------------------------------------
+
+
+@dataclass(frozen=True)
+class TypeTypeParam(TypeParam):
+    bound: TypeBound
+
+    def to_serial(self) -> stys.TypeTypeParam:
+        return stys.TypeTypeParam(b=self.bound)
+
+
+@dataclass(frozen=True)
+class BoundedNatParam(TypeParam):
+    upper_bound: int | None
+
+    def to_serial(self) -> stys.BoundedNatParam:
+        return stys.BoundedNatParam(bound=self.upper_bound)
+
+
+@dataclass(frozen=True)
+class OpaqueParam(TypeParam):
+    ty: Opaque
+
+    def to_serial(self) -> stys.OpaqueParam:
+        return stys.OpaqueParam(ty=self.ty.to_serial())
+
+
+@dataclass(frozen=True)
+class ListParam(TypeParam):
+    param: TypeParam
+
+    def to_serial(self) -> stys.ListParam:
+        return stys.ListParam(param=self.param.to_serial_root())
+
+
+@dataclass(frozen=True)
+class TupleParam(TypeParam):
+    params: list[TypeParam]
+
+    def to_serial(self) -> stys.TupleParam:
+        return stys.TupleParam(params=ser_it(self.params))
+
+
+@dataclass(frozen=True)
+class ExtensionsParam(TypeParam):
+    def to_serial(self) -> stys.ExtensionsParam:
+        return stys.ExtensionsParam()
+
+
+# ------------------------------------------
+# --------------- TypeArg ------------------
+# ------------------------------------------
+
+
+@dataclass(frozen=True)
+class TypeTypeArg(TypeArg):
+    ty: Type
+
+    def to_serial(self) -> stys.TypeTypeArg:
+        return stys.TypeTypeArg(ty=self.ty.to_serial_root())
+
+
+@dataclass(frozen=True)
+class BoundedNatArg(TypeArg):
+    n: int
+
+    def to_serial(self) -> stys.BoundedNatArg:
+        return stys.BoundedNatArg(n=self.n)
+
+
+@dataclass(frozen=True)
+class OpaqueArg(TypeArg):
+    ty: Opaque
+    value: Any
+
+    def to_serial(self) -> stys.OpaqueArg:
+        return stys.OpaqueArg(typ=self.ty.to_serial(), value=self.value)
+
+
+@dataclass(frozen=True)
+class SequenceArg(TypeArg):
+    elems: list[TypeArg]
+
+    def to_serial(self) -> stys.SequenceArg:
+        return stys.SequenceArg(elems=ser_it(self.elems))
+
+
+@dataclass(frozen=True)
+class ExtensionsArg(TypeArg):
+    extensions: ExtensionSet
+
+    def to_serial(self) -> stys.ExtensionsArg:
+        return stys.ExtensionsArg(es=self.extensions)
+
+
+@dataclass(frozen=True)
+class VariableArg(TypeArg):
+    idx: int
+    param: TypeParam
+
+    def to_serial(self) -> stys.VariableArg:
+        return stys.VariableArg(idx=self.idx, cached_decl=self.param.to_serial_root())
+
+
+# ----------------------------------------------
+# --------------- Type -------------------------
+# ----------------------------------------------
+
+
+@dataclass(frozen=True)
+class Array(Type):
+    ty: Type
+    size: int
+
+    def to_serial(self) -> stys.Array:
+        return stys.Array(ty=self.ty.to_serial_root(), len=self.size)
+
+
+@dataclass(frozen=True)
+class UnitSum(Type):
+    size: int
+
+    def to_serial(self) -> stys.UnitSum:
+        return stys.UnitSum(size=self.size)
+
+
+@dataclass()
+class Sum(Type):
+    variant_rows: list[TypeRow]
+
+    def to_serial(self) -> stys.GeneralSum:
+        return stys.GeneralSum(rows=[ser_it(row) for row in self.variant_rows])
+
+    def as_tuple(self) -> Tuple:
+        assert (
+            len(self.variant_rows) == 1
+        ), "Sum type must have exactly one row to be converted to a Tuple"
+        return Tuple(*self.variant_rows[0])
+
+
+@dataclass()
+class Tuple(Sum):
+    def __init__(self, *tys: Type):
+        self.variant_rows = [list(tys)]
+
+
+@dataclass(frozen=True)
+class Variable(Type):
+    idx: int
+    bound: TypeBound
+
+    def to_serial(self) -> stys.Variable:
+        return stys.Variable(i=self.idx, b=self.bound)
+
+
+@dataclass(frozen=True)
+class RowVariable(Type):
+    idx: int
+    bound: TypeBound
+
+    def to_serial(self) -> stys.RowVar:
+        return stys.RowVar(i=self.idx, b=self.bound)
+
+
+@dataclass(frozen=True)
+class USize(Type):
+    def to_serial(self) -> stys.USize:
+        return stys.USize()
+
+
+@dataclass(frozen=True)
+class Alias(Type):
+    name: str
+    bound: TypeBound
+
+    def to_serial(self) -> stys.Alias:
+        return stys.Alias(name=self.name, bound=self.bound)
+
+
+@dataclass(frozen=True)
+class FunctionType(Type):
+    input: list[Type]
+    output: list[Type]
+    extension_reqs: ExtensionSet = field(default_factory=ExtensionSet)
+
+    def to_serial(self) -> stys.FunctionType:
+        return stys.FunctionType(input=ser_it(self.input), output=ser_it(self.output))
+
+    @classmethod
+    def empty(cls) -> FunctionType:
+        return cls(input=[], output=[])
+
+
+@dataclass(frozen=True)
+class PolyFuncType(Type):
+    params: list[TypeParam]
+    body: FunctionType
+
+    def to_serial(self) -> stys.PolyFuncType:
+        return stys.PolyFuncType(
+            params=[p.to_serial_root() for p in self.params], body=self.body.to_serial()
+        )
+
+
+@dataclass
+class Opaque(Type):
+    id: str
+    bound: TypeBound
+    args: list[TypeArg] = field(default_factory=list)
+    extension: ExtensionId = ""
+
+    def to_serial(self) -> stys.Opaque:
+        return stys.Opaque(
+            extension=self.extension,
+            id=self.id,
+            args=[arg.to_serial_root() for arg in self.args],
+            bound=self.bound,
+        )
+
+
+@dataclass
+class QubitDef(Type):
+    def to_serial(self) -> stys.Qubit:
+        return stys.Qubit()
+
+
+Qubit = QubitDef()
+Bool = UnitSum(size=2)