Switch to nanobind (#839)

* mostly builds

* most tests pass

* fix circle build

* add back buffer protocol

* includes

* fix for py38

* limit to cpu device

* include

* fix stubs

* move signatures for docs

* stubgen + docs fix

* doc for compiled function, comments

docs/src/conf.py

@@ -29,8 +29,8 @@ autosummary_generate = True
 autosummary_filename_map = {"mlx.core.Stream": "stream_class"}
 
 intersphinx_mapping = {
-    "https://docs.python.org/3": None,
-    "https://numpy.org/doc/stable/": None,
+    "python": ("https://docs.python.org/3", None),
+    "numpy": ("https://numpy.org/doc/stable/", None),
 }
 
 templates_path = ["_templates"]
@@ -59,3 +59,14 @@ html_theme_options = {
 # -- Options for HTMLHelp output ---------------------------------------------
 
 htmlhelp_basename = "mlx_doc"
+
+
+def setup(app):
+    wrapped = app.registry.documenters["function"].can_document_member
+
+    def nanobind_function_patch(member: Any, *args, **kwargs) -> bool:
+        return "nanobind.nb_func" in str(type(member)) or wrapped(
+            member, *args, **kwargs
+        )
+
+    app.registry.documenters["function"].can_document_member = nanobind_function_patch

docs/src/install.rst

@@ -70,16 +70,13 @@ To build and install the MLX python library from source, first, clone MLX from
 
    git clone git@github.com:ml-explore/mlx.git mlx && cd mlx
 
-Make sure that you have `pybind11 <https://pybind11.readthedocs.io/en/stable/index.html>`_
-installed. You can install ``pybind11`` with ``pip``, ``brew`` or ``conda`` as follows:
+Install `nanobind <https://nanobind.readthedocs.io/en/latest/>`_ with:
 
 .. code-block:: shell
 
-    pip install "pybind11[global]"
-    conda install pybind11
-    brew install pybind11
+    pip install git+https://github.com/wjakob/nanobind.git
 
-Then simply build and install it using pip:
+Then simply build and install MLX using pip:
 
 .. code-block:: shell