7 add bools for numpy backend and cupy backend for conditional statements

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **Global Backend Control**:
     - `xp.set_backend(name)`: Globally switch the active backend at runtime.
     - `xp.use_backend(name)`: Context manager for temporary, scoped backend switching.
+    - `xp.numpy_backend` & `xp.cupy_backend`: Boolean properties to check the globally active backend.
 - **Synchronization**:
     - `xp.synchronize()`: Blocks until GPU operations are complete (no-op on CPU). Essential for accurate benchmarking.
 - **Developer Experience**:
@@ -25,7 +26,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 - **Dynamic Dispatch Architecture**: Refactored `src/cunumpy/xp.py` to use module-level `__getattr__`. This ensures that `cunumpy.<op>` calls always resolve to the currently active backend module, enabling seamless runtime switching via `set_backend`.
 - **Type Safety**: Updated `src/cunumpy/__init__.pyi` stubs to provide full IDE autocompletion and type-checking for all new API methods.
-- **Documentation**: Enhanced `README.md` with usage examples for the new backend control and synchronization features.
+- **Documentation**: 
+    - Simplified `README.md` and documentation to exclusively focus on PyPI installation (`pip install cunumpy`).
+    - Enhanced `quickstart.md` and `api.md` with usage examples for the new backend control and synchronization features.
+- **CI/CD**: Restricted GitHub Pages documentation deployment to the `devel` branch only.
 
 ### Fixed
 - Improved `ArrayBackend` initialization to fallback gracefully to NumPy if CuPy is requested but not installed.

docs/source/api.md

@@ -24,6 +24,12 @@ Returns `True` if the array is stored on a CPU (NumPy).
 
 ## Global Configuration
 
+### `numpy_backend`
+Boolean property that returns `True` if the currently active global backend is NumPy.
+
+### `cupy_backend`
+Boolean property that returns `True` if the currently active global backend is CuPy.
+
 ### `set_backend(backend_name)`
 Globally sets the active backend for all `cunumpy` operations. `backend_name` should be `"numpy"` or `"cupy"`.
 

src/cunumpy/__init__.py

@@ -23,9 +23,15 @@
     "use_backend",
     "set_backend",
     "synchronize",
+    "numpy_backend",
+    "cupy_backend",
 ]
 
 
 def __getattr__(name: str):
     """Set cunumpy.<name> to cunumpy.xp.<name> (NumPy/CuPy)."""
+    if name == "numpy_backend":
+        return xp.numpy_backend
+    if name == "cupy_backend":
+        return xp.cupy_backend
     return getattr(xp.xp, name)

src/cunumpy/__init__.pyi

@@ -19,3 +19,6 @@ def is_cpu(array: Any) -> bool: ...
 def use_backend(backend: str) -> Generator[None, None, None]: ...
 def set_backend(backend: str) -> None: ...
 def synchronize() -> None: ...
+
+numpy_backend: bool
+cupy_backend: bool

src/cunumpy/xp.py

@@ -92,6 +92,16 @@ def set_backend(backend: BackendType) -> None:
     array_backend._xp = array_backend._load_backend(backend)
 
 
+def _cupy_backend() -> bool:
+    """Check if the active global backend is CuPy."""
+    return array_backend.backend == "cupy"
+
+
+def _numpy_backend() -> bool:
+    """Check if the active global backend is NumPy."""
+    return array_backend.backend == "numpy"
+
+
 def synchronize() -> None:
     """Wait for all kernels in all streams on current device to complete."""
     if array_backend.backend == "cupy":
@@ -153,4 +163,8 @@ def is_cpu(array: Any) -> bool:
     def __getattr__(name):
         if name == "xp":
             return array_backend.xp
+        if name == "numpy_backend":
+            return _numpy_backend()
+        if name == "cupy_backend":
+            return _cupy_backend()
         raise AttributeError(f"module {__name__!r} has no attribute {name!r}")

tests/unit/test_app.py

@@ -29,6 +29,8 @@ def test_numpy_symbols_accessible():
         "use_backend",
         "set_backend",
         "synchronize",
+        "numpy_backend",
+        "cupy_backend",
         "xp",
     ]
     missing = [
@@ -114,6 +116,16 @@ def test_synchronize():
         xp.synchronize()
 
 
+def test_backend_bools():
+    with xp.use_backend("numpy"):
+        assert xp.numpy_backend is True
+        assert xp.cupy_backend is False
+
+    # Note: in test env without cupy, cupy_backend might be false
+    # even inside use_backend('cupy') if fallback occurs.
+    # Our implementation of use_backend calls _load_backend which returns np if cp missing.
+
+
 if __name__ == "__main__":
     test_xp_array()
     test_numpy_symbols_accessible()