From 04ed3299ef862c13a73efa874c09f372ff25de24 Mon Sep 17 00:00:00 2001
From: Seyon Sivarajah <seyon.sivarajah@quantinuum.com>
Date: Tue, 18 Jun 2024 17:09:30 +0100
Subject: [PATCH] refactor(hugr-py): common up a null check (#1205)

avoids some bugs I kept making because of name similarities
---
 hugr-py/src/hugr/_ops.py | 29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)

diff --git a/hugr-py/src/hugr/_ops.py b/hugr-py/src/hugr/_ops.py
index 026619890..1a390eeb1 100644
--- a/hugr-py/src/hugr/_ops.py
+++ b/hugr-py/src/hugr/_ops.py
@@ -90,15 +90,22 @@ def __call__(self) -> Command:
         return super().__call__()
 
 
+V = TypeVar("V")
+
+
+def _check_complete(v: V | None) -> V:
+    if v is None:
+        raise IncompleteOp()
+    return v
+
+
 @dataclass()
 class Output(DataflowOp, PartialOp):
     _types: tys.TypeRow | None = None
 
     @property
     def types(self) -> tys.TypeRow:
-        if self._types is None:
-            raise IncompleteOp()
-        return self._types
+        return _check_complete(self._types)
 
     def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> sops.Output:
         return sops.Output(parent=parent.idx, types=ser_it(self.types))
@@ -143,9 +150,7 @@ class MakeTupleDef(DataflowOp, PartialOp):
 
     @property
     def types(self) -> tys.TypeRow:
-        if self._types is None:
-            raise IncompleteOp()
-        return self._types
+        return _check_complete(self._types)
 
     def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> sops.MakeTuple:
         return sops.MakeTuple(
@@ -172,9 +177,7 @@ class UnpackTupleDef(DataflowOp, PartialOp):
 
     @property
     def types(self) -> tys.TypeRow:
-        if self._types is None:
-            raise IncompleteOp()
-        return self._types
+        return _check_complete(self._types)
 
     @property
     def num_out(self) -> int | None:
@@ -297,9 +300,7 @@ class DataflowBlock(DfParentOp):
 
     @property
     def sum_rows(self) -> list[tys.TypeRow]:
-        if self._sum_rows is None:
-            raise IncompleteOp()
-        return self._sum_rows
+        return _check_complete(self._sum_rows)
 
     @property
     def other_outputs(self) -> tys.TypeRow:
@@ -348,9 +349,7 @@ class ExitBlock(Op):
 
     @property
     def cfg_outputs(self) -> tys.TypeRow:
-        if self._cfg_outputs is None:
-            raise IncompleteOp()
-        return self._cfg_outputs
+        return _check_complete(self._cfg_outputs)
 
     def to_serial(self, node: Node, parent: Node, hugr: Hugr) -> sops.ExitBlock:
         return sops.ExitBlock(