[finsberg]

Summary

Three bugs that turned up while fixing the mypy errors on finsberg/fenicsx-compat, one commit each.

compute_extrema: kind was a default value, not an annotation

 def compute_extrema(
     u: ufl.core.expr.Expr,
-    kind=MinMaxFunc,
+    kind: MinMaxFunc,
     ...
-        raise ValueError("Unknown extrema {kind}, supports min and max only.")
+        raise ValueError(f"Unknown extrema {kind}, supports min and max only.")

Without kind, a call used to raise a misleading "Unknown extrema {kind}" error. Now kind is required, as it already is in find_cell_extrema. Every working call already passed it.

create_space_of_simple_functions: float32 meshes and int64 cell tags

+dtype = mesh.geometry.x.dtype
+_fe_constructor, _fem_constructor = FiniteElement_float{32,64}, FunctionSpace_float{32,64}  # by dtype
-el = basix.ufl.element("P", ..., discontinuous=True)
+el = basix.ufl.element("P", ..., discontinuous=True, dtype=dtype)
-adj_flattened = np.zeros_like(cell_tag.values)          # int64 tags -> int64 array
+adj_flattened = np.zeros(len(cell_tag.values), dtype=np.int32)
-dolfinx.cpp.fem.FunctionSpace_float64(mesh._cpp_object, ...)
+_fem_constructor(mesh._cpp_object, ...)

The float32/float64 choice follows create_geometry_function_space.

_extract_dtype (private): typed for what it is given

It was annotated as also taking a UFL expression, but a plain expression such as u * v raised AttributeError. Both callers (assemble_scalar and norm) only pass forms, so the annotation now says that. No change at runtime.

Evidence

• Before:

  test_material_space_dtypes[int32-float32]  TypeError: __init__(): incompatible function arguments   (FunctionSpace_float64)
  test_material_space_dtypes[int64-float32]  TypeError: __init__(): incompatible function arguments   (AdjacencyList_int32)
  test_material_space_dtypes[int64-float64]  TypeError: __init__(): incompatible function arguments   (AdjacencyList_int32)
  test_extrema_requires_kind                 ValueError: Unknown extrema {kind}, supports min and max only.
  test_extrema_unknown_kind                  Regex pattern did not match
  

  After: all 6 new tests pass, and so does the full suite against DOLFINx 0.12.0.dev0:

  pytest                 879 passed, 1154 skipped, 11 xfailed
  mpirun -n 3 pytest     881 passed, 1152 skipped, 11 xfailed   (every rank)
  mypy src tests         Success: no issues found in 43 source files
  

Merge Danger

Door: two-way

Each fix is a small, separate commit and can be reverted on its own.

Blast Radius: callers

• Calling compute_extrema without kind now raises TypeError instead of ValueError. Such a call never worked.
• create_space_of_simple_functions now accepts float32 meshes and int64 cell tags, which used to raise. float64 meshes with int32 tags behave as before.

🤖 Generated with Claude Code