Add in-place variants for infer_pauli_measurements, to_bloch,...

CHANGELOG.md

@@ -47,6 +47,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - #556, #563: Added a context variable `default_output_format` to unify the default output format for displaying `PauliFlow`, `XZCorrections`, `Pattern`, and `StateVec`.
 
+- #568:
+  - Added the following methods to `Pattern`. By default, they modify the pattern in place, with an optional `copy` parameter. If `copy=True`, a modified copy is returned instead.
+    - `apply`, an in-place variant of `map`,
+    - `blochify`, an in-place variant of `to_bloch`.
+  - All classes that have `subs` and `xreplace` methods (`Pattern`, `Circuit`, `OpenGraph`, `Measurement`, `PauliFlow`, `XZCorrections`, `DensityMatrix`) now derive from the `Parameterizable` class, which exposes the method `with_parameter` and `with_parameters`, with `subs` and `xreplace` as their respective aliases.
+  - `Pattern` and `Circuit` now derive from the `InplaceParameterizable` subclass, which additionally provides the following methods:
+    - `replace_parameter`, an in-place variant of `with_parameter` (or `subs`),
+    - `replace_parameters`, an in-place variant of `with_parameters` (or `xreplace`).
+
 ### Fixed
 
 - #454, #481: Ensure `Pattern.minimize_space` only reduces max-space and does not increase it.
@@ -128,6 +137,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - Dropped support for symbolic simulation and removed `Statevector.xreplace` and `Statevector.subs` methods.
   - Added method `DenseState.project_qubit` which defaults to calling `evolve_single` and `remove_qubit`. Added specialized code for this method in `Statevector` class.
   - Unified `test_statevec.py` and `test_statevec_backend.py` into a single file.
+
+- #568: Method `Pattern.infer_pauli_measurements` and function `transpile_swaps` now operate in place by default, with an optional `copy` parameter. If `copy=True`, a modified copy is returned instead.
 
 ## [0.3.5] - 2026-03-26
 

COMPATIBILITY.md

@@ -53,9 +53,4 @@ Graphix does not guarantee backwards compatibility between 0.x version releases.
     | `MatGF2.compute_rank` | `MatGF2.rank` |
     | `Statevec` | `Statevector` |
 
-
-
-
-
-
-
+- #568: Method `Pattern.infer_pauli_measurements` and function `transpile_swaps` now operate in place by default, with an optional `copy` parameter. If `copy=True`, a modified copy is returned instead.

examples/deutsch_jozsa.py

@@ -73,7 +73,7 @@
 # %%
 # Now we preprocess all Pauli measurements, which requires that we move inputs to N commands
 
-pattern = pattern.infer_pauli_measurements()
+pattern.infer_pauli_measurements()
 pattern.remove_pauli_measurements()
 print(
     pattern.to_ascii(

examples/mbqc_vqe.py

@@ -92,7 +92,7 @@ def build_mbqc_pattern(self, params: Iterable[ParameterizedAngle]) -> Pattern:
         pattern = circuit.transpile().pattern
         pattern.standardize()
         pattern.shift_signals()
-        pattern = pattern.infer_pauli_measurements()
+        pattern.infer_pauli_measurements()
         pattern.remove_pauli_measurements()
         pattern.minimize_space()
         return pattern

examples/qaoa.py

@@ -40,7 +40,7 @@
 # %%
 # perform Pauli measurements and plot the new (minimal) graph to perform the same quantum computation
 
-pattern = pattern.infer_pauli_measurements()
+pattern.infer_pauli_measurements()
 pattern.remove_pauli_measurements()
 pattern.draw(flow_from_pattern=False)
 

examples/qft_with_tn.py

@@ -67,7 +67,7 @@ def qft(circuit: Circuit, n: int) -> None:
 # Using graph rewriting rules, we can classically preprocess Pauli measurements.
 # We are currently improving the speed of this process by using rust-based graph manipulation backend.
 pattern.remove_input_nodes()
-pattern = pattern.infer_pauli_measurements()
+pattern.infer_pauli_measurements()
 pattern.remove_pauli_measurements(standardize=True)
 
 

examples/tn_simulation.py

@@ -85,7 +85,7 @@ def ansatz(
 # %%
 # Optimizing by removing Pauli measurements in the pattern.
 pattern.remove_input_nodes()
-pattern = pattern.infer_pauli_measurements()
+pattern.infer_pauli_measurements()
 pattern.remove_pauli_measurements(standardize=True)
 
 # %%
@@ -204,7 +204,7 @@ def cost(
     pattern.standardize()
     pattern.shift_signals()
     pattern.remove_input_nodes()
-    pattern = pattern.infer_pauli_measurements()
+    pattern.infer_pauli_measurements()
     pattern.remove_pauli_measurements(standardize=True)
     mbqc_tn = pattern.simulate(backend="tensornetwork", graph_prep="parallel")
     exp_val: float = 0

examples/visualization.py

@@ -37,7 +37,7 @@
 
 # %%
 # next, show the gflow:
-pattern = pattern.infer_pauli_measurements()
+pattern.infer_pauli_measurements()
 pattern.remove_pauli_measurements()
 pattern.draw(flow_from_pattern=False, measurement_labels=True)
 

graphix/flow/core.py

@@ -47,6 +47,7 @@
 )
 from graphix.fundamentals import AbstractMeasurement, AbstractPlanarMeasurement, Axis, Plane
 from graphix.measurements import Measurement
+from graphix.parameter import Parameterizable
 from graphix.pretty_print import OutputFormat, flow_to_str, xzcorr_to_str
 
 if TYPE_CHECKING:
@@ -74,7 +75,7 @@
 
 
 @dataclass(frozen=True)
-class XZCorrections(Generic[_AM_co]):
+class XZCorrections(Parameterizable, Generic[_AM_co]):
     """An unmutable dataclass providing a representation of XZ-corrections.
 
     Attributes
@@ -518,7 +519,10 @@ def draw(self, **options: Unpack[DrawKwargs]) -> None:
         gv = GraphVisualizer.from_xzcorrections(xz_corr=self, **options)
         gv.visualize()
 
-    def subs(self: XZCorrections[_M], variable: Parameter, substitute: ExpressionOrSupportsFloat) -> XZCorrections[_M]:
+    @override
+    def with_parameter(
+        self: XZCorrections[_M], variable: Parameter, substitute: ExpressionOrSupportsFloat
+    ) -> XZCorrections[_M]:
         """Substitute a parameter with a value or expression in all measurement angles of the open graph.
 
         Parameters
@@ -537,10 +541,11 @@ def subs(self: XZCorrections[_M], variable: Parameter, substitute: ExpressionOrS
         -----
         See notes and examples in :func:`OpenGraph.subs`.
         """
-        new_og = self.og.subs(variable, substitute)
+        new_og = self.og.with_parameter(variable, substitute)
         return dataclasses.replace(self, og=new_og)
 
-    def xreplace(
+    @override
+    def with_parameters(
         self: XZCorrections[_M], assignment: Mapping[Parameter, ExpressionOrSupportsFloat]
     ) -> XZCorrections[_M]:
         """Perform parallel substitution of multiple parameters in measurement angles of the open graph.
@@ -559,12 +564,12 @@ def xreplace(
         -----
         See notes and examples in :func:`OpenGraph.xreplace`.
         """
-        new_og = self.og.xreplace(assignment)
+        new_og = self.og.with_parameters(assignment)
         return dataclasses.replace(self, og=new_og)
 
 
 @dataclass(frozen=True)
-class PauliFlow(Generic[_AM_co]):
+class PauliFlow(Parameterizable, Generic[_AM_co]):
     """An unmutable dataclass providing a representation of a Pauli flow.
 
     Attributes
@@ -858,7 +863,8 @@ def draw(self, **options: Unpack[DrawKwargs]) -> None:
         gv = GraphVisualizer.from_flow(flow=self, **options)
         gv.visualize()
 
-    def subs(  # noqa: PYI019 Annotating with ``Self`` is not possible since ``self`` must be of parametric type ``Measurement``.
+    @override
+    def with_parameter(  # noqa: PYI019 Annotating with ``Self`` is not possible since ``self`` must be of parametric type ``Measurement``.
         self: _T_PauliFlowMeasurement, variable: Parameter, substitute: ExpressionOrSupportsFloat
     ) -> _T_PauliFlowMeasurement:
         """Substitute a parameter with a value or expression in all measurement angles of the open graph.
@@ -879,10 +885,11 @@ def subs(  # noqa: PYI019 Annotating with ``Self`` is not possible since ``self`
         -----
         See notes and examples in :func:`OpenGraph.subs`.
         """
-        new_og = self.og.subs(variable, substitute)
+        new_og = self.og.with_parameter(variable, substitute)
         return dataclasses.replace(self, og=new_og)
 
-    def xreplace(  # noqa: PYI019
+    @override
+    def with_parameters(  # noqa: PYI019
         self: _T_PauliFlowMeasurement, assignment: Mapping[Parameter, ExpressionOrSupportsFloat]
     ) -> _T_PauliFlowMeasurement:
         """Perform parallel substitution of multiple parameters in measurement angles of the open graph.
@@ -901,7 +908,7 @@ def xreplace(  # noqa: PYI019
         -----
         See notes and examples in :func:`OpenGraph.xreplace`.
         """
-        new_og = self.og.xreplace(assignment)
+        new_og = self.og.with_parameters(assignment)
         return dataclasses.replace(self, og=new_og)
 
     def is_focused(self) -> bool: