Refactor extension module definitions in setup.py

Separate Cython and C extension modules for clarity.

Author: chenxinye

setup.py

@@ -1,51 +1,44 @@
-# setup.py
 import sys
 from setuptools import setup, Extension
 from setuptools.command.build_ext import build_ext
 from Cython.Build import cythonize
 
-
 class CustomBuildExt(build_ext):
     def finalize_options(self):
         super().finalize_options()
         import numpy as np
         self.include_dirs.append(np.get_include())
 
-
 if sys.platform == "win32":
     c_args = ["/O2"]
 else:
     c_args = ["-O3"]
 
-
-ext_modules = [
+pyx_extensions = [
     Extension("classix.aggregate_ed_c", ["classix/aggregate_ed_c.pyx"], extra_compile_args=c_args),
     Extension("classix.aggregate_ed_cm", ["classix/aggregate_ed_cm.pyx"], extra_compile_args=c_args),
     Extension("classix.merge_ed_cm", ["classix/merge_ed_cm.pyx"], extra_compile_args=c_args),
     Extension("classix.merge_ed_cm_win", ["classix/merge_ed_cm_win.pyx"], extra_compile_args=c_args),
-
     Extension("classix.aggregate_md_cm", ["classix/aggregate_md_cm.pyx"], extra_compile_args=c_args),
     Extension("classix.merge_md_cm", ["classix/merge_md_cm.pyx"], extra_compile_args=c_args),
-
     Extension(
         "classix.aggregate_td_cm",
         ["classix/aggregate_td_cm.pyx"],
         language="c++",
         extra_compile_args=c_args,
     ),
-
     Extension("classix.merge_td_cm", ["classix/merge_td_cm.pyx"], extra_compile_args=c_args),
+]
 
+c_extensions = [
     Extension("spmv", ["classix/spmv.c"], extra_compile_args=c_args),
 ]
 
-
 setup(
     ext_modules=cythonize(
-        ext_modules,
+        pyx_extensions,
         compiler_directives={"language_level": "3"},
         annotate=False,
-    ),
+    ) + c_extensions,
     cmdclass={"build_ext": CustomBuildExt},
 )
-