Support numpy qid indexes (#6987)

* Support numpy qid indexes

* remove if check on _BaseLineQid.__hash__

Author: daxfohl

cirq-core/cirq/devices/grid_qubit.py

@@ -34,11 +34,9 @@ class _BaseGridQid(ops.Qid):
     _col: int
     _dimension: int
     _comp_key: Optional[Tuple[int, int]] = None
-    _hash: Optional[int] = None
+    _hash: int
 
     def __hash__(self) -> int:
-        if self._hash is None:
-            self._hash = ((self._dimension - 2) * 1_000_003 + self._col) * 1_000_003 + self._row
         return self._hash
 
     def __eq__(self, other) -> bool:
@@ -215,6 +213,9 @@ def __new__(cls, row: int, col: int, *, dimension: int) -> 'cirq.GridQid':
             dimension: The dimension of the qid's Hilbert space, i.e.
                 the number of quantum levels.
         """
+        row = int(row)
+        col = int(col)
+        dimension = int(dimension)
         key = (row, col, dimension)
         inst = cls._cache.get(key)
         if inst is None:
@@ -223,6 +224,7 @@ def __new__(cls, row: int, col: int, *, dimension: int) -> 'cirq.GridQid':
             inst._row = row
             inst._col = col
             inst._dimension = dimension
+            inst._hash = ((dimension - 2) * 1_000_003 + col) * 1_000_003 + row
             cls._cache[key] = inst
         return inst
 
@@ -378,12 +380,15 @@ def __new__(cls, row: int, col: int) -> 'cirq.GridQubit':
             row: the row coordinate
             col: the column coordinate
         """
+        row = int(row)
+        col = int(col)
         key = (row, col)
         inst = cls._cache.get(key)
         if inst is None:
             inst = super().__new__(cls)
             inst._row = row
             inst._col = col
+            inst._hash = col * 1_000_003 + row
             cls._cache[key] = inst
         return inst
 

cirq-core/cirq/devices/grid_qubit_test.py

@@ -391,3 +391,24 @@ def test_immutable():
 def test_complex():
     assert complex(cirq.GridQubit(row=1, col=2)) == 2 + 1j
     assert isinstance(complex(cirq.GridQubit(row=1, col=2)), complex)
+
+
+def test_numpy_index():
+    np5, np6, np3 = [np.int64(i) for i in [5, 6, 3]]
+    q = cirq.GridQubit(np5, np6)
+    hash(q)  # doesn't throw
+    assert q.row == 5
+    assert q.col == 6
+    assert q.dimension == 2
+    assert isinstance(q.row, int)
+    assert isinstance(q.col, int)
+    assert isinstance(q.dimension, int)
+
+    q = cirq.GridQid(np5, np6, dimension=np3)
+    hash(q)  # doesn't throw
+    assert q.row == 5
+    assert q.col == 6
+    assert q.dimension == 3
+    assert isinstance(q.row, int)
+    assert isinstance(q.col, int)
+    assert isinstance(q.dimension, int)

cirq-core/cirq/devices/line_qubit.py

@@ -30,11 +30,9 @@ class _BaseLineQid(ops.Qid):
 
     _x: int
     _dimension: int
-    _hash: Optional[int] = None
+    _hash: int
 
     def __hash__(self) -> int:
-        if self._hash is None:
-            self._hash = (self._dimension - 2) * 1_000_003 + self._x
         return self._hash
 
     def __eq__(self, other) -> bool:
@@ -193,13 +191,16 @@ def __new__(cls, x: int, dimension: int) -> 'cirq.LineQid':
             dimension: The dimension of the qid's Hilbert space, i.e.
                 the number of quantum levels.
         """
+        x = int(x)
+        dimension = int(dimension)
         key = (x, dimension)
         inst = cls._cache.get(key)
         if inst is None:
             cls.validate_dimension(dimension)
             inst = super().__new__(cls)
             inst._x = x
             inst._dimension = dimension
+            inst._hash = (dimension - 2) * 1_000_003 + x
             cls._cache[key] = inst
         return inst
 
@@ -301,10 +302,12 @@ def __new__(cls, x: int) -> 'cirq.LineQubit':
         Args:
             x: The x coordinate.
         """
+        x = int(x)
         inst = cls._cache.get(x)
         if inst is None:
             inst = super().__new__(cls)
             inst._x = x
+            inst._hash = x
             cls._cache[x] = inst
         return inst
 

cirq-core/cirq/devices/line_qubit_test.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import numpy as np
 import pytest
 
 import cirq
@@ -284,3 +285,20 @@ def test_numeric():
     assert isinstance(int(cirq.LineQubit(x=5)), int)
     assert isinstance(float(cirq.LineQubit(x=5)), float)
     assert isinstance(complex(cirq.LineQubit(x=5)), complex)
+
+
+def test_numpy_index():
+    np5 = np.int64(5)
+    q = cirq.LineQubit(np5)
+    assert hash(q) == 5
+    assert q.x == 5
+    assert q.dimension == 2
+    assert isinstance(q.x, int)
+    assert isinstance(q.dimension, int)
+
+    q = cirq.LineQid(np5, np.int64(3))
+    hash(q)  # doesn't throw
+    assert q.x == 5
+    assert q.dimension == 3
+    assert isinstance(q.x, int)
+    assert isinstance(q.dimension, int)