Merge branch 'main' into deprecate-rot-angles

Author: astralcai

doc/releases/changelog-dev.md

@@ -15,6 +15,58 @@
   The new function returns a tuple of four values, where the first three corresponds to the rotation
   angles of the ZYZ decomposition of this operator, and the last one corresponds to the global phase.
 
+* :func:`~.specs` will now output symbolic resource information when it encounters a loop that uses dynamic control-flow
+  that can't be resolved at compile time.
+  In such cases the returned :class:`~.resource.CircuitSpecs` will contain :class:`~.resource.SymbolicSpecsResources` instances instead of the usual :class:`~.resource.SpecsResources` instances.
+
+  ```python
+  @qp.qjit(autograph=True)
+  @qp.qnode(qp.device("lightning.qubit", wires=1))
+  def circuit(x):
+      qp.Hadamard(0)
+      qp.PauliX(0)
+      for _ in range(x):
+          qp.PauliX(0)
+      return qp.expval(qp.PauliX(0))
+
+  specs_result = qp.specs(circuit, level=0)(5)
+  ```
+
+  ```pycon
+  >>> print(specs_result)
+  Device: lightning.qubit
+  Device wires: 1
+  Shots: Shots(total=None)
+  Level: Before MLIR Passes
+  <BLANKLINE>
+  Symbolic Variables: a
+  Wire allocations: 1
+  Total gates: a + 2
+  Gate counts:
+  - Hadamard: 1
+  - PauliX: a + 1
+  Measurements:
+  - expval(PauliX): 1
+  Depth: Not computed
+
+  ```
+
+  These symbolic resources include expressions with variables which can substituted for concrete values to compute the associated resources for a circuit, via the ``subs`` method.
+
+  ```pycon
+  >>> res = specs_result.resources
+  >>> print(res.subs(a=5))
+  Wire allocations: 1
+  Total gates: 7
+  Gate counts:
+  - Hadamard: 1
+  - PauliX: 6
+  Measurements:
+  - expval(PauliX): 1
+  Depth: Not computed
+
+  ```
+
 * A new template for Fast Fermionic Fourier Transforms called :class:`~.FFFT` has been added.
   This algorithm is based on [Ferris (2013)](https://arxiv.org/abs/1310.7605) and applies to
   efficient simulation of quantum materials and chemistry systems.
@@ -46,7 +98,7 @@
 
   Alongside the addition of :class:`~.FFFT`, a new operation called :class:`~.TwoWireFFT`
   has been added to enable its implementation: the :class:`~.FFFT` operation is
-  decomposed recursively into :class:`~.FermionicSWAP` and :class:`~.TwoWireFFT` operations 
+  decomposed recursively into :class:`~.FermionicSWAP` and :class:`~.TwoWireFFT` operations
   (two-site Fermionic Fourier transforms).
 
 <h3>Improvements 🛠</h3>
@@ -92,7 +144,7 @@
   ```
   [(#9368)](https://github.com/PennyLaneAI/pennylane/pull/9368)
 
-* Updated `qp.registers` to accept empty registers (e.g., `qp.registers({"algo_wires": 5, "work_wires": 0})). 
+* Updated `qp.registers` to accept empty registers (e.g., `qp.registers({"algo_wires": 5, "work_wires": 0})).
   [(#9543)](https://github.com/PennyLaneAI/pennylane/pull/9543)
 
 * Removed instances of using the deprecated way to set shots on a device `device(..., shots=...)`.
@@ -150,7 +202,7 @@
     True
 
   ```
-  
+
 * Created a new ``labs.templates.LeftClassicalComparator`` template for performing an inequality
   test of a quantum register and an integer.
   [(#9308)](https://github.com/PennyLaneAI/pennylane/pull/9308)
@@ -175,12 +227,12 @@
     )
     return qp.sample(wires=3)
   ```
-  
+
   ```pycon
     >>> output = circuit(3, 2)
     >>> print(bool(output)) # 3 >= 2
     True
-  
+
   ```
 
 * Update phase gradient transforms to use ``BasisState`` instead of ``BasisEmbedding``.
@@ -360,6 +412,10 @@
 
 <h3>Bug fixes 🐛</h3>
 
+* Fixed a bug in `change_op_basis` where `TypeError` raised within the body of callable inputs were
+  accidentally being masked by internal try/except logic.
+  [(#9552)](https://github.com/PennyLaneAI/pennylane/pull/9552)
+  
 * Fixed a bug in unary iteration in `Select` where work wires were not restored correctly
   if the number of selected operators is notably smaller than the maximal capacity for the given
   number of control wires. This bug only surfaced for `partial=False`.
@@ -423,4 +479,5 @@ Andrija Paurevic,
 Francesco Pernice Botta,
 Jay Soni,
 Paul Haochen Wang,
-David Wierichs.
+David Wierichs,
+Jake Zaia.

pennylane/_version.py

@@ -16,4 +16,4 @@
 Version number (major.minor.patch[-label])
 """
 
-__version__ = "0.46.0-dev21"
+__version__ = "0.46.0-dev23"

pennylane/ops/op_math/change_op_basis.py

@@ -15,6 +15,7 @@
 This submodule defines a class for compute-uncompute patterns.
 """
 
+import inspect
 from collections import Counter, defaultdict
 from collections.abc import Callable
 from functools import reduce
@@ -39,14 +40,31 @@
 from .composite import CompositeOp, handle_recursion_error
 
 
-def _apply_op_or_func(op_or_func):
-    if isinstance(op_or_func, Callable):
-        try:
-            op_or_func()
-        except TypeError as e:
+def _validate_callable(func: Callable) -> None:
+    """Validates that a callable has no unbound mandatory parameters."""
+    sig = inspect.signature(func)
+
+    for param in sig.parameters.values():
+        # The function,
+        #
+        # def f(*args, **kwargs):
+        #     pass
+        #
+        # technically doesn't have any required parameters.
+        if param.kind in (inspect.Parameter.VAR_POSITIONAL, inspect.Parameter.VAR_KEYWORD):
+            continue
+
+        # If param has no default we can early exit
+        if param.default is inspect.Parameter.empty:
             raise TypeError(
-                "change_op_basis requires that Callable inputs have no parameters. functools.partial can be used to achieve this."
-            ) from e
+                "change_op_basis requires that Callable inputs have no unbound mandatory parameters. Please use functools.partial to bind them."
+            )
+
+
+def _apply_op_or_func(op_or_func):
+    if callable(op_or_func):
+        _validate_callable(op_or_func)
+        op_or_func()
     elif isinstance(op_or_func, Operator):
         type(op_or_func)._unflatten(*op_or_func._flatten())  # pylint: disable=protected-access
     elif math.is_abstract(op_or_func):
@@ -58,13 +76,9 @@ def _apply_op_or_func(op_or_func):
 
 
 def _convert_to_prod(op_or_func):
-    if isinstance(op_or_func, Callable):
-        try:
-            return prod(op_or_func)()
-        except TypeError as e:
-            raise TypeError(
-                "change_op_basis requires that Callable inputs have no parameters. functools.partial can be used to achieve this."
-            ) from e
+    if callable(op_or_func):
+        _validate_callable(op_or_func)
+        return prod(op_or_func)()
     if isinstance(op_or_func, Operator):
         return op_or_func
     raise TypeError(

pennylane/resource/__init__.py

@@ -37,7 +37,9 @@
     :toctree: api
 
     ~CircuitSpecs
+    ~Expression
     ~SpecsResources
+    ~SymbolicSpecsResources
 
     ~resources_from_tape
 
@@ -138,6 +140,7 @@ def circuit(theta):
     Resources,
     ResourcesOperation,
     SpecsResources,
+    SymbolicSpecsResources,
     CircuitSpecs,
     add_in_series,
     add_in_parallel,
@@ -146,4 +149,5 @@ def circuit(theta):
     resources_from_tape,
     substitute,
 )
+from .expression import Expression
 from .specs import specs