update flattenrelabelregisters

pytket/binders/passes.cpp

@@ -752,9 +752,12 @@ PYBIND11_MODULE(passes, m) {
       "FlattenRelabelRegistersPass", &gen_flatten_relabel_registers_pass,
       "Removes empty Quantum wires from the Circuit and relabels all Qubit to "
       "a register from passed name. \n\n:param label: Name to relabel "
-      "remaining Qubit to, default 'q'.\n:return: A pass that removes empty "
+      "remaining Qubit to, default 'q'.\n:param relabel_classical_expressions: "
+      "Whether to relabel arguments of expressions held in `ClassicalExpBox`. "
+      "\n:return: A pass that removes empty "
       "wires and relabels.",
-      py::arg("label") = q_default_reg());
+      py::arg("label") = q_default_reg(),
+      py::arg("relabel_classical_expressions") = true);
 
   m.def(
       "RenameQubitsPass", &gen_rename_qubits_pass,

pytket/docs/changelog.rst

@@ -13,6 +13,8 @@ Features:
 * Add `custom_deserialisation` argument to `BasePass` and `SequencePass` 
   `from_dict` method to support construction of `CustomPass` from json.
 * Add `timeout` argument to `GreedyPauliSimp`.
+* Add option to not relabel `ClassicalExpBox` when calling `rename_units`
+  and `flatten_registers`
 
 Fixes:
 

pytket/pytket/_tket/circuit.pyi

@@ -2104,9 +2104,11 @@ class Circuit:
         :param types: the set of operation types of interest
         :return: the circuit depth with respect to operations matching an element of `types`
         """
-    def flatten_registers(self) -> dict[pytket._tket.unit_id.UnitID, pytket._tket.unit_id.UnitID]:
+    def flatten_registers(self, relabel_classical_expression: bool = True) -> dict[pytket._tket.unit_id.UnitID, pytket._tket.unit_id.UnitID]:
         """
         Combines all qubits into a single register namespace with the default name, and likewise for bits
+        
+        :param relabel_classical_expression: Determines whether python classical expressions held in `ClassicalExpBox` have their expression relabelled to match relabelled Bit.
         """
     def free_symbols(self) -> set[sympy.Symbol]:
         """

pytket/pytket/_tket/passes.pyi

@@ -410,11 +410,12 @@ def FlattenRegisters() -> BasePass:
     """
     Merges all quantum and classical registers into their respective default registers with contiguous indexing.
     """
-def FlattenRelabelRegistersPass(label: str = 'q') -> BasePass:
+def FlattenRelabelRegistersPass(label: str = 'q', relabel_classical_expressions: bool = True) -> BasePass:
     """
     Removes empty Quantum wires from the Circuit and relabels all Qubit to a register from passed name. 
     
     :param label: Name to relabel remaining Qubit to, default 'q'.
+    :param relabel_classical_expressions: Whether to relabel arguments of expressions held in `ClassicalExpBox`. 
     :return: A pass that removes empty wires and relabels.
     """
 def FullMappingPass(arc: pytket._tket.architecture.Architecture, placer: pytket._tket.placement.Placement, config: typing.Sequence[pytket._tket.mapping.RoutingMethod]) -> BasePass:

schemas/compiler_pass_v1.json

@@ -648,9 +648,10 @@
           },
           "then": {
             "required": [
-              "label"
+              "label",
+              "relabel_classical_registers"
             ],
-            "maxProperties": 2
+            "maxProperties": 3
           }
         },
         {

tket/include/tket/Predicates/PassGenerators.hpp

@@ -110,7 +110,7 @@ PassPtr gen_clifford_push_through_pass();
  * Qubits removed from the Circuit are preserved in the bimap, but not updated
  * to a new labelling.
  */
-PassPtr gen_flatten_relabel_registers_pass(const std::string& label);
+PassPtr gen_flatten_relabel_registers_pass(const std::string& label, bool relabel_classical_expressions = true);
 /**
  * Pass to rename some or all qubits according to the given map.
  *

tket/src/Predicates/CompilerPass.cpp

@@ -469,7 +469,7 @@ PassPtr deserialise(
       pp = gen_euler_pass(q, p, s);
     } else if (passname == "FlattenRelabelRegistersPass") {
       pp = gen_flatten_relabel_registers_pass(
-          content.at("label").get<std::string>());
+          content.at("label").get<std::string>(), content.at("relabel_classical_expressions").get<bool>());
     } else if (passname == "RoutingPass") {
       Architecture arc = content.at("architecture").get<Architecture>();
       std::vector<RoutingMethodPtr> con = content.at("routing_config");

tket/src/Predicates/PassGenerators.cpp

@@ -354,7 +354,7 @@ PassPtr gen_clifford_push_through_pass() {
   return std::make_shared<StandardPass>(precons, t, pc, j);
 }
 
-PassPtr gen_flatten_relabel_registers_pass(const std::string& label) {
+PassPtr gen_flatten_relabel_registers_pass(const std::string& label, bool relabel_classical_expressions) {
   Transform t =
       Transform([=](Circuit& circuit, std::shared_ptr<unit_bimaps_t> maps) {
         unsigned n_qubits = circuit.n_qubits();
@@ -366,7 +366,7 @@ PassPtr gen_flatten_relabel_registers_pass(const std::string& label) {
           relabelling_map.insert({all_qubits[i], Qubit(label, i)});
         }
 
-        circuit.rename_units(relabelling_map);
+        circuit.rename_units(relabelling_map, relabel_classical_expressions);
         changed |= update_maps(maps, relabelling_map, relabelling_map);
         return changed;
       });
@@ -376,6 +376,7 @@ PassPtr gen_flatten_relabel_registers_pass(const std::string& label) {
   nlohmann::json j;
   j["name"] = "FlattenRelabelRegistersPass";
   j["label"] = label;
+  j["relabel_classical_expressions"] = relabel_classical_expressions;
   return std::make_shared<StandardPass>(precons, t, postcons, j);
 }