changed doc in foreach, more checks in foreach test

BQSKit · Oct 17, 2023 · 5e1319f · 5e1319f
1 parent 54dafc8
commit 5e1319f
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Showing 2 changed files with 40 additions and 11 deletions.
diff --git a/bqskit/passes/control/foreach.py b/bqskit/passes/control/foreach.py
@@ -41,7 +41,20 @@ class ForEachBlockPass(BasePass):
     pass_down_block_specific_key_prefix = (
         'ForEachBlockPass_specific_pass_down_'
     )
-    """Key for injecting a block specific pass data."""
+    """
+    Data specific to the processing of individual blocks in a partitioned
+    circuit can be injected into the `PassData` in `run` by using this prefix.
+
+    The expected type of the associated value is `dict[int, Any]`, where
+    integer (sub-)keys correspond to block numbers in a partitioned quantum
+    circuit.
+
+    Pseudocode example for seed circuits:
+        seeds = {block_id: [seed_circuit_a, seed_circuit_b, ...], ...}
+        key = self.pass_down_block_specific_key_prefix + 'seed_circuits'
+        seed_updater = UpdateDataPass(key, seeds)
+        workflow = Workflow([..., seed_updater, ForEachBlockPass(...), ...])
+    """
 
     def __init__(
         self,

diff --git a/tests/passes/control/test_foreachblock.py b/tests/passes/control/test_foreachblock.py
@@ -138,28 +138,44 @@ def test_no_hang_on_empty_collection(compiler: Compiler) -> None:
 
 
 def test_pass_down_seeds(compiler: Compiler) -> None:
-    circuit = Circuit(3)
-    circuit.append_gate(CNOTGate(), (0, 1))
+    circuit = Circuit(4)
+    circuit.append_gate(CNOTGate(), (0, 2))
     circuit.append_gate(CNOTGate(), (1, 2))
+    circuit.append_gate(CNOTGate(), (1, 3))
+    circuit.append_gate(CNOTGate(), (2, 3))
 
     seed = Circuit(3)
-    seed.append_gate(CNOTGate(), (0, 1))
+    seed.append_gate(CNOTGate(), (0, 2))
     seed.append_gate(CNOTGate(), (1, 2))
 
-    # Manually sed seed for block 0
-    seeds = {0: [seed]}
-
-    key = 'ForEachBlockPass_specific_pass_down_seed_circuits'
+    # Manually set seed for blocks 0 and 1
+    seeds = {0: [seed], 1: [seed]}
 
     partitioner = QuickPartitioner()
-    updater = UpdateDataPass(key, seeds)
     qsearch = QSearchSynthesisPass()
     foreach = ForEachBlockPass(qsearch)
     unfolder = UnfoldPass()
-    workflow = Workflow([partitioner, updater, foreach, unfolder])
+
+    key = foreach.pass_down_block_specific_key_prefix + 'seed_circuits'
+    updater = UpdateDataPass(key, seeds)
+
+    # For checking specific pass down data exists
+    workflow_1 = Workflow([partitioner, updater])
+    # For checking specific pass down data can be used
+    workflow_2 = Workflow([partitioner, updater, foreach, unfolder])
+
+    # Check existence of block specific keys
+    partitioned, data = compiler.compile(
+        circuit, workflow_1, request_data=True,
+    )
+    for i, block in enumerate(partitioned):
+        data[key][i] == seeds[i]
+
+    # Check that block specific data is usable
     compiled, data = compiler.compile(
-        circuit, workflow, request_data=True,
+        circuit, workflow_2, request_data=True,
     )
     dist = compiled.get_unitary().get_distance_from(circuit.get_unitary())
     assert dist <= 1e-5
     assert key in data
+    assert data[key] == seeds