Adding array-api-compat fallback

.github/workflows/ci.yml

@@ -56,7 +56,7 @@ jobs:
         with:
           python-version: ${{ matrix.env.python }}
       - name: create environment
-        run: uvx hatch env create ${{ matrix.env.name }}
+        run: uvx hatch -v env create ${{ matrix.env.name }}
       - name: run tests with coverage
         run: |
           uvx hatch run ${{ matrix.env.name }}:run-cov

.pre-commit-config.yaml

@@ -32,6 +32,7 @@ repos:
     - array-api-compat>=1.13
     - dask>=2026.1
     - h5py>=3.15
+    - jax>=0.10
     - numba>=0.63
     - packaging>=26
     - pytest>=9

pyproject.toml

@@ -22,8 +22,8 @@ classifiers = [
   "Programming Language :: Python :: 3.13",
   "Programming Language :: Python :: 3.14",
 ]
-dynamic = [ "description", "readme", "version" ]
-dependencies = [ "numpy>=2" ]
+dynamic = [ "version" ]
+dependencies = [ "array-api-compat", "numpy>=2" ]
 optional-dependencies.accel = [ "numba>=0.57" ]
 optional-dependencies.dask = [ "dask>=2023.6.1" ]
 optional-dependencies.full = [ "fast-array-utils[accel,dask,sparse]", "h5py", "zarr" ]
@@ -37,9 +37,10 @@ entry-points.pytest11.fast_array_utils = "testing.fast_array_utils.pytest"
 [dependency-groups]
 test = [
   "anndata",
-  "fast-array-utils[accel]",
+  "fast-array-utils[full]",
+  "jax",
+  "jaxlib",
   "scikit-learn",
-  "zarr",
   { include-group = "test-min" },
 ]
 doc = [
@@ -66,12 +67,8 @@ envs.docs.scripts.clean = "git clean -fdX docs"
 envs.docs.scripts.open = "python -m webbrowser -t docs/_build/html/index.html"
 envs.hatch-test.default-args = []
 envs.hatch-test.dependency-groups = [ "test-min" ]
-# TODO: remove scipy once https://github.com/pypa/hatch/pull/2127 is released
-envs.hatch-test.extra-dependencies = [ "ipykernel", "ipycytoscape", "scipy" ]
+envs.hatch-test.extra-dependencies = [ "ipykernel", "ipycytoscape" ]
 envs.hatch-test.env-vars.CODSPEED_PROFILE_FOLDER = "test-data/codspeed"
-envs.hatch-test.overrides.matrix.extras.features = [
-  { if = [ "full" ], value = "full" },
-]
 envs.hatch-test.overrides.matrix.extras.dependency-groups = [
   { if = [ "full" ], value = "test" },
 ]
@@ -85,9 +82,10 @@ envs.hatch-test.matrix = [
   { python = [ "3.14", "3.12" ], extras = [ "full", "min" ] },
   { python = [ "3.12" ], extras = [ "full" ], resolution = [ "lowest" ] },
 ]
-metadata.hooks.docstring-description = {}
-metadata.hooks.fancy-pypi-readme.content-type = "text/x-rst"
-metadata.hooks.fancy-pypi-readme.fragments = [ { path = "README.rst", start-after = ".. begin" } ]
+# TODO: re-activate incl. `dynamic = [ "description", "readme", ... ]` after https://github.com/pypa/hatch/issues/2252
+# metadata.hooks.docstring-description = {}
+# metadata.hooks.fancy-pypi-readme.content-type = "text/x-rst"
+# metadata.hooks.fancy-pypi-readme.fragments = [ { path = "README.rst", start-after = ".. begin" } ]
 version.source = "vcs"
 version.raw-options = { local_scheme = "no-local-version" }  # be able to publish dev version
 

src/fast_array_utils/conv/__init__.py

@@ -38,13 +38,19 @@ def to_dense(x: GpuArray | types.CupySpMatrix, /, *, order: Literal["K", "A", "C
 def to_dense(x: GpuArray | types.CupySpMatrix, /, *, order: Literal["K", "A", "C", "F"] = "K", to_cpu_memory: Literal[True]) -> NDArray[Any]: ...
 
 
+@overload
+def to_dense[A: types.HasArrayNamespace](x: A, /, *, order: Literal["K", "A", "C", "F"] = "K", to_cpu_memory: Literal[False] = False) -> A: ...
+@overload
+def to_dense[A: types.HasArrayNamespace](x: A, /, *, order: Literal["K", "A", "C", "F"] = "K", to_cpu_memory: Literal[True]) -> NDArray[Any]: ...
+
+
 def to_dense(
-    x: CpuArray | GpuArray | DiskArray | types.CSDataset | types.DaskArray | types.sparray | types.spmatrix | types.CupySpMatrix,
+    x: CpuArray | GpuArray | DiskArray | types.CSDataset | types.DaskArray | types.sparray | types.spmatrix | types.CupySpMatrix | types.HasArrayNamespace,
     /,
     *,
     order: Literal["K", "A", "C", "F"] = "K",
     to_cpu_memory: bool = False,
-) -> NDArray[Any] | types.DaskArray | types.CupyArray:
+) -> NDArray[Any] | types.DaskArray | types.CupyArray | types.HasArrayNamespace:
     r"""Convert x to a dense array.
 
     If ``to_cpu_memory`` is :data:`False`, :class:`dask.array.Array`\ s and

src/fast_array_utils/conv/_to_dense.py

@@ -21,7 +21,7 @@
 # fallback’s arg0 type has to include types of registered functions
 @singledispatch
 def to_dense_(
-    x: CpuArray | GpuArray | DiskArray | types.DaskArray | types.sparray | types.spmatrix | types.CupySpMatrix,
+    x: CpuArray | GpuArray | DiskArray | types.DaskArray | types.sparray | types.spmatrix | types.CupySpMatrix | types.HasArrayNamespace,
     /,
     *,
     order: Literal["K", "A", "C", "F"] = "K",
@@ -39,6 +39,13 @@ def _to_dense_cs(x: types.spmatrix | types.sparray, /, *, order: Literal["K", "A
     return scipy.to_dense(x, order=sparse_order(x, order=order))
 
 
+@to_dense_.register(np.ndarray)
+def _to_dense_numpy(x: np.ndarray, /, *, order: Literal["K", "A", "C", "F"] = "K", to_cpu_memory: bool = False) -> np.ndarray:
+    # to bypass the _to_dense_array_api path
+    del to_cpu_memory
+    return np.asarray(x, order=order)
+
+
 @to_dense_.register(types.DaskArray)
 def _to_dense_dask(x: types.DaskArray, /, *, order: Literal["K", "A", "C", "F"] = "K", to_cpu_memory: bool = False) -> NDArray[Any] | types.DaskArray:
     from . import to_dense
@@ -69,6 +76,13 @@ def _to_dense_cupy(x: GpuArray, /, *, order: Literal["K", "A", "C", "F"] = "K",
     return x.get(order="A") if to_cpu_memory else x
 
 
+@to_dense_.register(types.HasArrayNamespace)
+def _to_dense_array_api[A: types.HasArrayNamespace](x: A, /, *, order: Literal["K", "A", "C", "F"] = "K", to_cpu_memory: bool = False) -> A | np.ndarray:
+    if to_cpu_memory:
+        return np.asarray(x, order=order)
+    return x
+
+
 def sparse_order(x: types.spmatrix | types.sparray | types.CupySpMatrix | types.CSDataset, /, *, order: Literal["K", "A", "C", "F"]) -> Literal["C", "F"]:
     if TYPE_CHECKING:
         from scipy.sparse._base import _spbase

src/fast_array_utils/stats/__init__.py

@@ -37,14 +37,16 @@ def is_constant(x: NDArray[Any] | types.CSBase, /, *, axis: Literal[0, 1]) -> ND
 def is_constant(x: types.CupyArray, /, *, axis: Literal[0, 1]) -> types.CupyArray: ...
 @overload
 def is_constant(x: types.DaskArray, /, *, axis: Literal[0, 1] | None = None) -> types.DaskArray: ...
+@overload
+def is_constant[A: types.HasArrayNamespace](x: A, /, *, axis: Literal[0, 1] | None = None) -> bool | A: ...
 
 
 def is_constant(
-    x: NDArray[Any] | types.CSBase | types.CupyArray | types.DaskArray,
+    x: NDArray[Any] | types.CSBase | types.CupyArray | types.DaskArray | types.HasArrayNamespace,
     /,
     *,
     axis: Literal[0, 1] | None = None,
-) -> bool | NDArray[np.bool] | types.CupyArray | types.DaskArray:
+) -> bool | NDArray[np.bool] | types.CupyArray | types.DaskArray | types.HasArrayNamespace:
     """Check whether values in array are constant.
 
     Parameters
@@ -90,15 +92,17 @@ def mean(x: CpuArray | DiskArray, /, *, axis: Literal[0, 1], dtype: DTypeLike |
 def mean(x: GpuArray, /, *, axis: Literal[0, 1], dtype: DTypeLike | None = None) -> types.CupyArray: ...
 @overload
 def mean(x: types.DaskArray, /, *, axis: Literal[0, 1], dtype: ToDType[Any] | None = None) -> types.DaskArray: ...
+@overload
+def mean[A: types.HasArrayNamespace](x: A, /, *, axis: Literal[0, 1] | None = None, dtype: DTypeLike | None = None) -> A: ...
 
 
 def mean(
-    x: CpuArray | GpuArray | DiskArray | types.DaskArray,
+    x: CpuArray | GpuArray | DiskArray | types.DaskArray | types.HasArrayNamespace,
     /,
     *,
     axis: Literal[0, 1] | None = None,
     dtype: DTypeLike | None = None,
-) -> NDArray[np.number[Any]] | types.CupyArray | np.number[Any] | types.DaskArray:
+) -> NDArray[np.number[Any]] | types.CupyArray | np.number[Any] | types.DaskArray | types.HasArrayNamespace:
     """Mean over both or one axis.
 
     Parameters
@@ -145,10 +149,10 @@ def mean_var(x: CpuArray, /, *, axis: Literal[0, 1], correction: int = 0) -> tup
 def mean_var(x: GpuArray, /, *, axis: Literal[0, 1], correction: int = 0) -> tuple[types.CupyArray, types.CupyArray]: ...
 @overload
 def mean_var(x: types.DaskArray, /, *, axis: Literal[0, 1] | None = None, correction: int = 0) -> tuple[types.DaskArray, types.DaskArray]: ...
-
-
+@overload
+def mean_var[A: types.HasArrayNamespace](x: A, /, *, axis: Literal[0, 1] | None = None, correction: int = 0) -> tuple[A, A]: ...
 def mean_var(
-    x: CpuArray | GpuArray | types.DaskArray,
+    x: CpuArray | GpuArray | types.DaskArray | types.HasArrayNamespace,
     /,
     *,
     axis: Literal[0, 1] | None = None,
@@ -158,6 +162,7 @@ def mean_var(
     | tuple[NDArray[np.float64], NDArray[np.float64]]
     | tuple[types.CupyArray, types.CupyArray]
     | tuple[types.DaskArray, types.DaskArray]
+    | tuple[types.HasArrayNamespace, types.HasArrayNamespace]
 ):
     """Mean and variance over both or one axis.
 
@@ -214,13 +219,13 @@ def _mk_generic_op(op: DtypeOps) -> StatFunDtype: ...
 # https://github.com/scverse/fast-array-utils/issues/52
 def _mk_generic_op(op: Ops) -> StatFunNoDtype | StatFunDtype:
     def _generic_op(
-        x: CpuArray | GpuArray | DiskArray | types.DaskArray,
+        x: CpuArray | GpuArray | DiskArray | types.DaskArray | types.HasArrayNamespace,
         /,
         *,
         axis: Literal[0, 1] | None = None,
         dtype: DTypeLike | None = None,
         keep_cupy_as_array: bool = False,
-    ) -> NDArray[Any] | np.number[Any] | types.CupyArray | types.DaskArray:
+    ) -> NDArray[Any] | np.number[Any] | types.CupyArray | types.DaskArray | types.HasArrayNamespace:
         from ._generic_ops import generic_op
 
         assert dtype is None or op in get_args(DtypeOps), f"`dtype` is not supported for operation {op!r}"
@@ -249,8 +254,10 @@ def min(x: GpuArray, /, *, axis: None, keep_cupy_as_array: Literal[True]) -> typ
 def min(x: GpuArray, /, *, axis: Literal[0, 1], keep_cupy_as_array: bool = False) -> types.CupyArray: ...
 @overload
 def min(x: types.DaskArray, /, *, axis: Literal[0, 1] | None = None, keep_cupy_as_array: bool = False) -> types.DaskArray: ...
+@overload
+def min[A: types.HasArrayNamespace](x: A, /, *, axis: Literal[0, 1] | None = None, keep_cupy_as_array: bool = False) -> A: ...
 def min(
-    x: CpuArray | GpuArray | DiskArray | types.DaskArray,
+    x: CpuArray | GpuArray | DiskArray | types.DaskArray | types.HasArrayNamespace,
     /,
     *,
     axis: Literal[0, 1] | None = None,
@@ -304,8 +311,10 @@ def max(x: GpuArray, /, *, axis: None, keep_cupy_as_array: Literal[True]) -> typ
 def max(x: GpuArray, /, *, axis: Literal[0, 1], keep_cupy_as_array: bool = False) -> types.CupyArray: ...
 @overload
 def max(x: types.DaskArray, /, *, axis: Literal[0, 1] | None = None, keep_cupy_as_array: bool = False) -> types.DaskArray: ...
+@overload
+def max[A: types.HasArrayNamespace](x: A, /, *, axis: Literal[0, 1] | None = None, keep_cupy_as_array: bool = False) -> A: ...
 def max(
-    x: CpuArray | GpuArray | DiskArray | types.DaskArray,
+    x: CpuArray | GpuArray | DiskArray | types.DaskArray | types.HasArrayNamespace,
     /,
     *,
     axis: Literal[0, 1] | None = None,
@@ -359,14 +368,16 @@ def sum(x: GpuArray, /, *, axis: None = None, dtype: DTypeLike | None = None, ke
 def sum(x: GpuArray, /, *, axis: Literal[0, 1], dtype: DTypeLike | None = None, keep_cupy_as_array: bool = False) -> types.CupyArray: ...
 @overload
 def sum(x: types.DaskArray, /, *, axis: Literal[0, 1] | None = None, dtype: DTypeLike | None = None, keep_cupy_as_array: bool = False) -> types.DaskArray: ...
+@overload
+def sum[A: types.HasArrayNamespace](x: A, /, *, axis: Literal[0, 1] | None = None, dtype: DTypeLike | None = None, keep_cupy_as_array: bool = False) -> A: ...
 def sum(
-    x: CpuArray | GpuArray | DiskArray | types.DaskArray,
+    x: CpuArray | GpuArray | DiskArray | types.DaskArray | types.HasArrayNamespace,
     /,
     *,
     axis: Literal[0, 1] | None = None,
     dtype: DTypeLike | None = None,
     keep_cupy_as_array: bool = False,
-) -> NDArray[Any] | types.CupyArray | np.number[Any] | types.DaskArray:
+) -> NDArray[Any] | types.CupyArray | np.number[Any] | types.DaskArray | types.HasArrayNamespace:
     """Sum over both or one axis.
 
     Parameters

src/fast_array_utils/stats/_generic_ops.py

@@ -22,34 +22,32 @@
     type ComplexAxis = tuple[Literal[0], Literal[1]] | tuple[Literal[0, 1]] | Literal[0, 1] | None
 
 
-def _run_numpy_op(
-    x: CpuArray | GpuArray | DiskArray | types.DaskArray,
+@singledispatch
+def generic_op(
+    x: CpuArray | GpuArray | DiskArray | types.DaskArray | types.HasArrayNamespace,
+    /,
     op: Ops,
     *,
     axis: Literal[0, 1] | None = None,
     dtype: DTypeLike | None = None,
+    keep_cupy_as_array: bool = False,
 ) -> NDArray[Any] | np.number[Any] | types.CupyArray | types.DaskArray:
-    arr = cast("NDArray[Any] | np.number[Any] | types.CupyArray | types.CupyCOOMatrix | types.DaskArray", getattr(np, op)(x, axis=axis, **_dtype_kw(dtype, op)))
-    return arr.toarray() if isinstance(arr, types.CupyCOOMatrix) else arr
+    raise NotImplementedError  # pragma: no cover
 
 
-@singledispatch
-def generic_op(
-    x: CpuArray | GpuArray | DiskArray | types.DaskArray,
+@generic_op.register(np.ndarray | types.H5Dataset | types.ZarrArray)
+# register explicitly to avoid the array API path and performance slow down
+def _generic_op_numpy_disk(
+    x: np.ndarray | DiskArray,
     /,
     op: Ops,
     *,
     axis: Literal[0, 1] | None = None,
     dtype: DTypeLike | None = None,
     keep_cupy_as_array: bool = False,
-) -> NDArray[Any] | np.number[Any] | types.CupyArray | types.DaskArray:
+) -> NDArray[Any] | np.number[Any]:
     del keep_cupy_as_array
-    if TYPE_CHECKING:
-        # these are never passed to this fallback function, but `singledispatch` wants them
-        assert not isinstance(x, types.CSBase | types.DaskArray | types.CupyArray | types.CupyCSMatrix)
-        # np supports these, but doesn’t know it. (TODO: test cupy)
-        assert not isinstance(x, types.ZarrArray | types.H5Dataset)
-    return cast("NDArray[Any] | np.number[Any]", _run_numpy_op(x, op, axis=axis, dtype=dtype))
+    return getattr(np, op)(x, axis=axis, **_dtype_kw(dtype, op))  # type: ignore[no-any-return]
 
 
 @generic_op.register(types.CupyArray | types.CupyCSMatrix)
@@ -62,7 +60,8 @@ def _generic_op_cupy(
     dtype: DTypeLike | None = None,
     keep_cupy_as_array: bool = False,
 ) -> types.CupyArray | np.number[Any]:
-    arr = cast("types.CupyArray", _run_numpy_op(x, op, axis=axis, dtype=dtype))
+    arr = cast("types.CupyArray | types.CupyCOOMatrix", getattr(np, op)(x, axis=axis, **_dtype_kw(dtype, op)))
+    arr = arr.toarray() if isinstance(arr, types.CupyCOOMatrix) else arr
     return cast("np.number[Any]", arr.get()[()]) if not keep_cupy_as_array and axis is None else arr.squeeze()
 
 
@@ -109,3 +108,22 @@ def _generic_op_dask(
         dtype = getattr(np, op)(np.zeros(1, dtype=x.dtype)).dtype
 
     return _dask_inner(x, op, axis=axis, dtype=dtype, keep_cupy_as_array=keep_cupy_as_array)
+
+
+@generic_op.register(types.HasArrayNamespace)
+def _generic_op_array_api[A: types.HasArrayNamespace](
+    x: A,
+    /,
+    op: Ops,
+    *,
+    axis: Literal[0, 1] | None = None,
+    dtype: DTypeLike | None = None,
+    keep_cupy_as_array: bool = False,
+) -> A:
+    """Handle arrays with native array API support."""
+    del keep_cupy_as_array
+
+    import array_api_compat
+
+    xp = array_api_compat.array_namespace(x)
+    return getattr(xp, op)(x, axis=axis, **_dtype_kw(dtype, op))  # type: ignore[no-any-return]

src/fast_array_utils/stats/_is_constant.py

@@ -2,7 +2,7 @@
 from __future__ import annotations
 
 from functools import partial, singledispatch
-from typing import TYPE_CHECKING, cast
+from typing import TYPE_CHECKING
 
 import numba
 import numpy as np
@@ -19,29 +19,29 @@
 
 @singledispatch
 def is_constant_(
-    a: NDArray[Any] | types.CSBase | types.CupyArray | types.DaskArray,
+    a: NDArray[Any] | types.CSBase | types.CupyArray | types.DaskArray | types.HasArrayNamespace,
     /,
     *,
     axis: Literal[0, 1] | None = None,
 ) -> bool | NDArray[np.bool] | types.CupyArray | types.DaskArray:  # pragma: no cover
-    raise NotImplementedError
+    raise NotImplementedError  # pragma: no cover
 
 
-@is_constant_.register(np.ndarray | types.CupyArray)
+@is_constant_.register(np.ndarray | types.CupyArray | types.HasArrayNamespace)
 def _is_constant_ndarray(a: NDArray[Any] | types.CupyArray, /, *, axis: Literal[0, 1] | None = None) -> bool | NDArray[np.bool] | types.CupyArray:
     # Should eventually support nd, not now.
     match axis:
         case None:
-            return bool((a == a.flat[0]).all())
+            return bool((a == a.reshape(-1)[0]).all())
         case 0:
             return _is_constant_rows(a.T)
         case 1:
             return _is_constant_rows(a)
 
 
 def _is_constant_rows(a: NDArray[Any] | types.CupyArray) -> NDArray[np.bool] | types.CupyArray:
-    b = np.broadcast_to(a[:, 0][:, np.newaxis], a.shape)
-    return cast("NDArray[np.bool]", (a == b).all(axis=1))
+    # broadcasts without needing np.broadcast_to
+    return (a == a[:, 0:1]).all(axis=1)
 
 
 @is_constant_.register(types.CSBase)

src/fast_array_utils/stats/_mean.py

@@ -18,12 +18,12 @@
 
 
 def mean_(
-    x: CpuArray | GpuArray | DiskArray | types.DaskArray,
+    x: CpuArray | GpuArray | DiskArray | types.DaskArray | types.HasArrayNamespace,
     /,
     *,
     axis: Literal[0, 1] | None = None,
     dtype: DTypeLike | None = None,
-) -> NDArray[np.number[Any]] | np.number[Any] | types.DaskArray:
+) -> NDArray[np.number[Any]] | np.number[Any] | types.DaskArray | types.HasArrayNamespace:
     total = sum(x, axis=axis, dtype=dtype)  # type: ignore[misc,arg-type]
     n = np.prod(x.shape) if axis is None else x.shape[axis]
     return total / n  # type: ignore[no-any-return]