[Quantum Chinese Chess] Add SplitJump and MergeJump

unitary/examples/quantum_chinese_chess/move.py

@@ -114,6 +114,8 @@ class Jump(QuantumEffect):
     - CAPTURE
     - EXCLUDED
     - BASIC
+
+    All types of pieces could make Jump move.
     """
 
     def __init__(
@@ -176,3 +178,62 @@ def effect(self, *objects) -> Iterator[cirq.Operation]:
         target_0.reset(source_0)
         source_0.reset()
         return iter(())
+
+
+class SplitJump(QuantumEffect):
+    """SplitJump from source_0 to target_0 and target_1. The only accepted (default) move_variant is
+    - BASIC.
+
+    All types of pieces could make SplitJump move, except KING. This is implemented with a
+    PhasedSplit().
+    """
+
+    def __init__(
+        self,
+    ):
+        return
+
+    def num_dimension(self) -> Optional[int]:
+        return 2
+
+    def num_objects(self) -> Optional[int]:
+        return 3
+
+    def effect(self, *objects) -> Iterator[cirq.Operation]:
+        source_0, target_0, target_1 = objects
+        # Make the split jump.
+        source_0.is_entangled = True
+        alpha.PhasedSplit()(source_0, target_0, target_1)
+        # Pass the classical properties of the source piece to the target pieces.
+        target_0.reset(source_0)
+        target_1.reset(source_0)
+        return iter(())
+
+
+class MergeJump(QuantumEffect):
+    """MergeJump from source_0 to source_1 to target_0. The only accepted (default) move_variant is
+    - BASIC.
+
+    All types of pieces could make MergeJump move, except KING.
+    """
+
+    def __init__(
+        self,
+    ):
+        return
+
+    def num_dimension(self) -> Optional[int]:
+        return 2
+
+    def num_objects(self) -> Optional[int]:
+        return 3
+
+    def effect(self, *objects) -> Iterator[cirq.Operation]:
+        source_0, source_1, target_0 = objects
+        # Make the merge jump.
+        alpha.PhasedMove(-0.5)(source_0, target_0)
+        alpha.PhasedMove(-0.5)(source_0, target_0)
+        alpha.PhasedMove(-0.5)(source_1, target_0)
+        # Pass the classical properties of the source pieces to the target piece.
+        target_0.reset(source_0)
+        return iter(())

unitary/examples/quantum_chinese_chess/move_test.py

@@ -11,7 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from unitary.examples.quantum_chinese_chess.move import Move, Jump
+from unitary.examples.quantum_chinese_chess.move import *
 from unitary.examples.quantum_chinese_chess.board import Board
 from unitary.examples.quantum_chinese_chess.piece import Piece
 import pytest
@@ -143,7 +143,7 @@ def test_to_str():
 
 
 def test_jump_classical():
-    # Target is empty.
+    """Target is empty."""
     board = set_board(["a1", "b1"])
     world = board.board
     # TODO(): try move all varaibles declarations of a1 = world["a1"] into a function.
@@ -156,7 +156,7 @@ def test_jump_classical():
 
 
 def test_jump_capture_quantum_source():
-    # Source is in quantum state.
+    """Source is in quantum state."""
     board = set_board(["a1", "b1"])
     world = board.board
     alpha.PhasedSplit()(world["a1"], world["a2"], world["a3"])
@@ -175,7 +175,7 @@ def test_jump_capture_quantum_source():
 
 
 def test_jump_capture_quantum_target():
-    # Target is in quantum state.
+    """Target is in quantum state."""
     board = set_board(["a1", "b1"])
     world = board.board
     alpha.PhasedSplit()(world["b1"], world["b2"], world["b3"])
@@ -187,7 +187,7 @@ def test_jump_capture_quantum_target():
 
 
 def test_jump_capture_quantum_source_and_target():
-    # Both source and target are in quantum state.
+    """Both source and target are in quantum state."""
     board = set_board(["a1", "b1"])
     world = board.board
     alpha.PhasedSplit()(world["a1"], world["a2"], world["a3"])
@@ -216,7 +216,7 @@ def test_jump_capture_quantum_source_and_target():
 
 
 def test_jump_excluded_quantum_target():
-    # Target is in quantum state.
+    """Target is in quantum state."""
     board = set_board(["a1", "b1"])
     world = board.board
     alpha.PhasedSplit()(world["b1"], world["b2"], world["b3"])
@@ -232,7 +232,7 @@ def test_jump_excluded_quantum_target():
 
 
 def test_jump_excluded_quantum_source_and_target():
-    # Both source and target are in quantum state.
+    """Both source and target are in quantum state."""
     board = set_board(["a1", "b1"])
     world = board.board
     alpha.PhasedSplit()(world["a1"], world["a2"], world["a3"])
@@ -252,7 +252,7 @@ def test_jump_excluded_quantum_source_and_target():
 
 
 def test_jump_basic():
-    # Source is in quantum state.
+    """Source is in quantum state."""
     board = set_board(["a1"])
     world = board.board
     alpha.PhasedSplit()(world["a1"], world["a2"], world["a3"])
@@ -261,3 +261,123 @@ def test_jump_basic():
     assert len(board_probabilities) == 2
     assert_fifty_fifty(board_probabilities, locations_to_bitboard(["d1"]))
     assert_fifty_fifty(board_probabilities, locations_to_bitboard(["a3"]))
+
+
+def test_split_jump_classical_source():
+    """Source is in classical state."""
+    board = set_board(["a1"])
+    world = board.board
+    SplitJump()(world["a1"], world["a2"], world["a3"])
+    board_probabilities = get_board_probability_distribution(board, 1000)
+    assert len(board_probabilities) == 2
+    assert_fifty_fifty(board_probabilities, locations_to_bitboard(["a2"]))
+    assert_fifty_fifty(board_probabilities, locations_to_bitboard(["a3"]))
+    assert world["a2"].type_ == Type.ROOK
+    assert world["a2"].color == Color.RED
+    assert world["a2"].is_entangled == True
+    assert world["a3"].type_ == Type.ROOK
+    assert world["a3"].color == Color.RED
+    assert world["a3"].is_entangled == True
+
+
+def test_split_jump_quantum_source():
+    """Source is in quantum state."""
+    board = set_board(["a1"])
+    world = board.board
+    alpha.PhasedSplit()(world["a1"], world["a2"], world["a3"])
+    SplitJump()(world["a3"], world["a4"], world["a5"])
+    assert_sample_distribution(
+        board,
+        {
+            locations_to_bitboard(["a2"]): 0.5,
+            locations_to_bitboard(["a4"]): 0.25,
+            locations_to_bitboard(["a5"]): 0.25,
+        },
+    )
+    assert world["a4"].is_entangled == True
+    assert world["a5"].is_entangled == True
+
+
+def test_merge_jump_perfect_merge():
+    """Two quantum pieces split from one source could be merge back to one."""
+    board = set_board(["a1"])
+    world = board.board
+    SplitJump()(world["a1"], world["a2"], world["a3"])
+    MergeJump()(world["a2"], world["a3"], world["a1"])
+    assert_samples_in(board, {locations_to_bitboard(["a1"]): 1.0})
+
+
+def test_merge_jump_imperfect_merge_scenario_1():
+    """Imperfect merge scenario 1"""
+    board = set_board(["a1"])
+    world = board.board
+    SplitJump()(world["a1"], world["a2"], world["a3"])
+    SplitJump()(world["a3"], world["a4"], world["a5"])
+    # a2 has prob. 0.5 to be occupied, while a4 has prob. 0.25 to be occupied
+    MergeJump()(world["a2"], world["a4"], world["a6"])
+    # Accoding to matrix calculations, the ending coefficient of
+    # a5 to be occupied: -1/2;
+    # a6 to be occupied: 1/2 + i/2/sqrt(2)
+    # a4 to be occupied: -i/2 -1/2/sqrt(2)
+    # a2 to be occupied: 0
+    assert_sample_distribution(
+        board,
+        {
+            locations_to_bitboard(["a5"]): 1.0 / 4,
+            locations_to_bitboard(["a6"]): 3.0 / 8,
+            locations_to_bitboard(["a4"]): 3.0 / 8,
+        },
+    )
+
+
+def test_merge_jump_imperfect_merge_scenario_2():
+    """Imperfect merge scenario 2
+    Two quantum pieces split from two sources could not be merge into to one.
+    """
+    board = set_board(["a1", "b1"])
+    world = board.board
+    SplitJump()(world["a1"], world["a2"], world["a3"])
+    SplitJump()(world["b1"], world["b2"], world["b3"])
+    MergeJump()(world["a2"], world["b2"], world["c2"])
+    # According to matrix calculations, the ending coefficient of
+    # [a3, b3]: 1/2
+    # [a3, c2]: i/2/sqrt(2)
+    # [a3, b2]: -1/2/sqrt(2)
+    # [b3, c2]: i/2/sqrt(2)
+    # [b2, b3]: 1/2/sqrt(2)
+    # [b2, c2]: 1/2
+    assert_sample_distribution(
+        board,
+        {
+            locations_to_bitboard(["a3", "b3"]): 1.0 / 4,
+            locations_to_bitboard(["a3", "c2"]): 1.0 / 8,
+            locations_to_bitboard(["a3", "b2"]): 1.0 / 8,
+            locations_to_bitboard(["b3", "c2"]): 1.0 / 8,
+            locations_to_bitboard(["b2", "b3"]): 1.0 / 8,
+            locations_to_bitboard(["b2", "c2"]): 1.0 / 4,
+        },
+    )
+
+
+def test_merge_jump_imperfect_merge_scenario_3():
+    """Imperfect merge scenario 3.
+    This is a simplied version of the scenario above, where we unhook a3 and b3.
+    """
+    board = set_board(["a1", "b1"])
+    world = board.board
+    SplitJump()(world["a1"], world["a2"], world["a3"])
+    SplitJump()(world["b1"], world["b2"], world["b3"])
+    board.board.unhook(world["a3"])
+    board.board.unhook(world["b3"])
+    # Now the only quantum pieces in the board are a2 and b2.
+    MergeJump()(world["a2"], world["b2"], world["c2"])
+    # The expected distribution is same as above by summing over a3 and b3.
+    assert_sample_distribution(
+        board,
+        {
+            locations_to_bitboard([]): 1.0 / 4,
+            locations_to_bitboard(["c2"]): 1.0 / 4,
+            locations_to_bitboard(["b2"]): 1.0 / 4,
+            locations_to_bitboard(["b2", "c2"]): 1.0 / 4,
+        },
+    )