Add pluggable backend dispatch system

docs/api.md

@@ -86,6 +86,19 @@ import squidpy as sq
     tl.var_by_distance
 ```
 
+## Settings
+
+```{eval-rst}
+.. currentmodule:: squidpy._backends._settings
+
+.. autoclass:: _Settings
+    :members: backend, use_backend, available_backends, get_backend
+
+.. data:: squidpy.settings
+
+    The global settings instance. See :class:`~squidpy._backends._settings._Settings`.
+```
+
 ## Datasets
 ```{eval-rst}
 .. module:: squidpy.datasets

pyproject.toml

@@ -76,6 +76,12 @@ dependencies = [
   "xarray>=2024.10",
   "zarr>=3",
 ]
+optional-dependencies.cu12 = [
+  "rapids-singlecell-cu12[rapids]",
+]
+optional-dependencies.cu13 = [
+  "rapids-singlecell-cu13[rapids]",
+]
 optional-dependencies.dev = [
   "hatch>=1.9",
   "ipykernel",

src/squidpy/__init__.py

@@ -4,6 +4,7 @@
 from importlib.metadata import PackageMetadata
 
 from squidpy import datasets, experimental, gr, im, pl, read, tl
+from squidpy._backends import settings
 
 try:
     md: PackageMetadata = metadata.metadata(__name__)
@@ -15,4 +16,4 @@
 
 del metadata, md
 
-__all__ = ["datasets", "experimental", "gr", "im", "pl", "read", "tl"]
+__all__ = ["datasets", "experimental", "gr", "im", "pl", "read", "settings", "tl"]

src/squidpy/_backends/__init__.py

@@ -0,0 +1,9 @@
+"""Pluggable backend dispatch system for squidpy."""
+
+from __future__ import annotations
+
+from squidpy._backends._dispatch import dispatch
+from squidpy._backends._registry import available_backend_names, get_backend
+from squidpy._backends._settings import settings
+
+__all__ = ["dispatch", "get_backend", "available_backend_names", "settings"]