Update for command classes

graphix/command.py

@@ -8,6 +8,7 @@
 from pydantic import BaseModel
 
 from graphix.pauli import Plane
+from graphix.parameter import ExpressionOrFloat
 
 Node = int
 
@@ -48,7 +49,7 @@ class M(Command):
     kind: CommandKind = CommandKind.M
     node: Node
     plane: Plane = Plane.XY
-    angle: float = 0.0
+    angle: ExpressionOrFloat = 0.0
     s_domain: list[Node] = []
     t_domain: list[Node] = []
     vop: int = 0

graphix/instruction.py

@@ -6,6 +6,7 @@
 from pydantic import BaseModel
 
 from graphix.pauli import Plane
+from graphix.parameter import ExpressionOrFloat
 
 
 class InstructionKind(enum.Enum):
@@ -18,7 +19,7 @@ class InstructionKind(enum.Enum):
     X = "X"
     Y = "Y"
     Z = "Z"
-    I = "I"
+    I = "I"  # noqa: E741
     M = "M"
     RX = "RX"
     RY = "RY"
@@ -58,7 +59,7 @@ class RotationInstruction(OneQubitInstruction):
     Rotation instruction base class model.
     """
 
-    angle: float
+    angle: ExpressionOrFloat
 
 
 class OneControlInstruction(OneQubitInstruction):
@@ -166,7 +167,7 @@ class Z(OneQubitInstruction):
     kind: InstructionKind = InstructionKind.Z
 
 
-class I(OneQubitInstruction):
+class I(OneQubitInstruction):  # noqa: E742
     """
     I circuit instruction.
     """
@@ -181,7 +182,7 @@ class M(OneQubitInstruction):
 
     kind: InstructionKind = InstructionKind.M
     plane: Plane
-    angle: float
+    angle: ExpressionOrFloat
 
 
 class RX(RotationInstruction):

graphix/parameter.py

@@ -8,8 +8,12 @@
 
 from __future__ import annotations
 
-from abc import ABC, abstractmethod
 import numbers
+from abc import ABC, abstractmethod
+import pydantic
+import pydantic_core
+import typing
+
 
 class Expression(ABC):
     """Expression with parameters."""
@@ -89,22 +93,31 @@ def __str__(self) -> str: ...
     @abstractmethod
     def subs(self, variable: Parameter, value: ExpressionOrNumber) -> ExpressionOrNumber: ...
 
-    @abstractmethod
-    def flatten(self) -> ExpressionOrNumber: ...
+    @classmethod
+    def __get_pydantic_core_schema__(
+        cls, source_type: typing.Any, handler: pydantic.GetCoreSchemaHandler
+    ) -> pydantic_core.CoreSchema:
+        def check_expression(obj) -> Expression:
+            if not isinstance(obj, Expression):
+                raise ValueError("Expression expected")
+            return obj
 
-    @abstractmethod
-    def conj(self) -> ExpressionOrNumber: ...
+        return pydantic_core.core_schema.no_info_plain_validator_function(function=check_expression)
 
 
 class PlaceholderOperationError(ValueError):
     def __init__(self):
-        super().__init__("Placeholder angles do not support any form of computation before substitution. Either use `subst` with an actual value before the computation, or use a symbolic parameter implementation, such that https://github.com/TeamGraphix/graphix-symbolic .")
+        super().__init__(
+            "Placeholder angles do not support any form of computation before substitution. Either use `subst` with an actual value before the computation, or use a symbolic parameter implementation, such that https://github.com/TeamGraphix/graphix-symbolic ."
+        )
 
 
 class Parameter(Expression):
     """Abstract class for substituable parameter."""
+
     ...
 
+
 class Placeholder(Parameter):
     """Placeholder for measurement angles, which allows the pattern optimizations
     without specifying measurement angles for measurement commands.
@@ -133,12 +146,11 @@ def __str__(self) -> str:
         return self.__name
 
     def subs(self, variable: Parameter, value: ExpressionOrNumber) -> ExpressionOrNumber:
-        if self == variable:
+        if self is variable:
             if isinstance(value, numbers.Number):
                 return complex(value)
             return value
-        else:
-            return self
+        return self
 
     def __mul__(self, other) -> ExpressionOrNumber:
         return NotImplemented
@@ -206,17 +218,8 @@ def conjugate(self) -> ExpressionOrNumber:
     def sqrt(self) -> ExpressionOrNumber:
         raise PlaceholderOperationError()
 
-    def subs(self, variable: Parameter, value: ExpressionOrNumber) -> ExpressionOrNumber:
-        if variable is self:
-            return value
-        return self
-
-    def flatten(self) -> ExpressionOrNumber:
-        raise PlaceholderOperationError()
-
-    def conj(self) -> ExpressionOrNumber:
-        raise PlaceholderOperationError()
 
+ExpressionOrFloat = Expression | float
 
 ExpressionOrNumber = Expression | numbers.Number
 

graphix/pattern.py

@@ -4,16 +4,16 @@
 
 from __future__ import annotations
 
-from copy import deepcopy
 import numbers
+from copy import deepcopy
 
 import networkx as nx
 import numpy as np
 
 import graphix.clifford
+import graphix.parameter
 import graphix.pauli
 from graphix import command
-import graphix.parameter
 from graphix.clifford import CLIFFORD_CONJ, CLIFFORD_MEASURE, CLIFFORD_TO_QASM3
 from graphix.device_interface import PatternRunner
 from graphix.gflow import find_flow, find_gflow, get_layers
@@ -985,7 +985,6 @@ def get_meas_plane(self):
             list of planes representing measurement plane for each node.
         """
         meas_plane = dict()
-        order = [graphix.pauli.Axis.X, graphix.pauli.Axis.Y, graphix.pauli.Axis.Z]
         for cmd in self.__seq:
             if cmd.kind == command.CommandKind.M:
                 mplane = cmd.plane
@@ -1419,8 +1418,8 @@ def to_qasm3(self, filename):
                     file.write("// measurement result of qubit q" + str(id) + "\n")
                     file.write("bit c" + str(id) + " = " + str(res) + ";\n")
                     file.write("\n")
-            for command in self.__seq:
-                for line in cmd_to_qasm3(command):
+            for cmd in self.__seq:
+                for line in cmd_to_qasm3(cmd):
                     file.write(line)
 
     def is_parameterized(self) -> bool:
@@ -1430,7 +1429,7 @@ def is_parameterized(self) -> bool:
         expression that is not a number, typically an instance of `sympy.Expr`
         (but we don't force to choose `sympy` here).
         """
-        return any(not isinstance(cmd[3], numbers.Number) for cmd in self if cmd[0] == "M")
+        return any(not isinstance(cmd.angle, numbers.Number) for cmd in self if cmd.kind == command.CommandKind.M)
 
     def subs(self, variable, substitute) -> Pattern:
         """Return a copy of the pattern where all occurrences of the
@@ -1447,9 +1446,8 @@ def subs(self, variable, substitute) -> Pattern:
         """
         result = Pattern(input_nodes=self.input_nodes)
         for cmd in self:
-            if cmd[0] == "M":
-                new_cmd = cmd.copy()
-                new_cmd[3] = graphix.parameter.subs(new_cmd[3], variable, substitute)
+            if cmd.kind == command.CommandKind.M:
+                new_cmd = cmd.model_copy(update={"angle": graphix.parameter.subs(cmd.angle, variable, substitute)})
                 result.add(new_cmd)
             else:
                 result.add(cmd)

graphix/sim/density_matrix.py

@@ -329,7 +329,14 @@ def subs(self, variable, substitute) -> DensityMatrix:
 class DensityMatrixBackend(Backend):
     """MBQC simulator with density matrix method."""
 
-    def __init__(self, pattern, max_qubit_num=12, pr_calc=True, input_state: Data = graphix.states.BasicStates.PLUS, rng: np.random.Generator | None = None):
+    def __init__(
+        self,
+        pattern,
+        max_qubit_num=12,
+        pr_calc=True,
+        input_state: Data = graphix.states.BasicStates.PLUS,
+        rng: np.random.Generator | None = None,
+    ):
         """
         Parameters
         ----------

graphix/sim/statevec.py

@@ -9,8 +9,8 @@
 import numpy as np
 import numpy.typing as npt
 
-import graphix.pauli
 import graphix.parameter
+import graphix.pauli
 import graphix.sim.base_backend
 import graphix.states
 import graphix.types