chore: rename nlz to ntz

docs/unitary_hack/issues.md

@@ -3,6 +3,6 @@
 - [Improvements to the API docs](https://github.com/PsiQ/bartiq/issues/193)
 - [Add function for calculating `circuit_volume`](https://github.com/PsiQ/bartiq/issues/150)
 - [Fix displaying resource name `local_highwater`.](https://github.com/PsiQ/bartiq/issues/163)
-- [Passing a non-integer into nlz results in unhelpful error message.](https://github.com/PsiQ/bartiq/issues/180)
+- [Passing a non-integer into ntz results in unhelpful error message.](https://github.com/PsiQ/bartiq/issues/180)
 - [Improve visualisation methods in Bartiq](https://github.com/PsiQ/bartiq/issues/188)
 - [Add convenience functions for finding subroutines](https://github.com/PsiQ/bartiq/issues/185)

src/bartiq/symbolics/sympy_interpreter.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import operator
+import warnings
 from typing import Any
 
 from sympy import (
@@ -143,30 +144,42 @@ def eval(cls, p, n):
         return orig_multiplicity(p, n) if isinstance(p, Integer) and isinstance(n, Integer) else None
 
 
-class nlz(Function):
+class ntz(Function):
     @classmethod
     def eval(cls, n):
         """
         Returns the number of trailing zeros in the binary representation of n.
         Only defined for non-negative integers.
         Returns 0 for input 0.
-        For symbolic input, returns unevaluated nlz(n).
+        For symbolic input, returns unevaluated ntz(n).
         Raises:
             TypeError: If input is not an integer (when numeric).
             ValueError: If input is a negative integer.
         """
         # Numeric evaluation
         if n.is_number:
             if not n.is_integer:
-                raise TypeError(f"nlz requires integer argument; found {n}")
+                raise TypeError(f"ntz requires integer argument; found {n}")
             n = int(n)
             if n < 0:
-                raise ValueError(f"nlz requires non-negative integer; found {n}")
+                raise ValueError(f"ntz requires non-negative integer; found {n}")
             if n == 0:
                 return 0
             return (n & -n).bit_length() - 1
 
 
+class nlz(ntz):
+    """Deprecated alias for ntz; use ntz instead."""
+
+    def __new__(cls, n, *args, **kwargs):
+        warnings.warn(
+            "nlz is deprecated and will be removed in a future release; use ntz instead",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return super().__new__(cls, n, *args, **kwargs)
+
+
 class Max(Function):
     """A custom implementation of Max.
 
@@ -242,6 +255,7 @@ def eval(cls, *args):
     "gamma": gamma,
     "heaviside": Heaviside,
     "multiplicity": multiplicity,
+    "ntz": ntz,
     "nlz": nlz,
 }