Add numpy feature for automatic mapping of numpy::ndarray

Signed-off-by: Andrej Orsula <[email protected]>

README.md

@@ -86,6 +86,11 @@ The workspace contains these packages:
 - **[pyo3_bindgen_engine](pyo3_bindgen_engine):** The underlying engine for generation of bindings
 - **[pyo3_bindgen_macros](pyo3_bindgen_macros):** Procedural macros for in-place generation
 
+Features of `pyo3_bindgen`:
+
+- **`macros` \[experimental\]:** Enables `import_python!` macro from `pyo3_bindgen_macros` crate
+- **`numpy` \[experimental\]:** Enables type mapping between Python [`numpy::ndarray`](https://numpy.org/doc/stable/reference/generated/numpy.ndarray.html) and Rust [`numpy::PyArray`](https://docs.rs/numpy/latest/numpy/array/struct.PyArray.html)
+
 ## Instructions
 
 ### <a href="#-option-1-build-script"><img src="https://rustacean.net/assets/rustacean-flat-noshadow.svg" width="16" height="16"></a> Option 1: Build script

pyo3_bindgen/Cargo.toml

@@ -18,12 +18,10 @@ pyo3_bindgen_macros = { workspace = true, optional = true }
 
 [features]
 default = []
-macros = ["pyo3_bindgen_macros"]
-
-[lib]
-name = "pyo3_bindgen"
-path = "src/lib.rs"
-crate-type = ["rlib"]
+# Enables `import_python!` macro from `pyo3_bindgen_macros` crate
+macros = ["dep:pyo3_bindgen_macros"]
+# Enables type mapping between Python `numpy::ndarray` and Rust `numpy::PyArray`
+numpy = ["pyo3_bindgen_engine/numpy"]
 
 [package.metadata.docs.rs]
 all-features = true

pyo3_bindgen_engine/Cargo.toml

@@ -29,13 +29,9 @@ prettyplease = { workspace = true }
 [build-dependencies]
 pyo3-build-config = { workspace = true }
 
-[lib]
-name = "pyo3_bindgen_engine"
-path = "src/lib.rs"
-crate-type = ["rlib"]
-
 [features]
 default = []
+numpy = []
 
 [[bench]]
 name = "bindgen"

pyo3_bindgen_engine/src/typing/into_rs.rs

@@ -316,7 +316,9 @@ impl Type {
         }
 
         // Try to map the local types
-        if let Some(relative_path) = local_types.get(&Path::from_py(&type_name)) {
+        let type_name_without_delimiters =
+            type_name.split_once('[').map(|s| s.0).unwrap_or(&type_name);
+        if let Some(relative_path) = local_types.get(&Path::from_py(type_name_without_delimiters)) {
             let relative_path: syn::Path = relative_path.try_into().unwrap();
             return OutputType::new(
                 quote!(::pyo3::Bound<'py, #relative_path>),
@@ -331,9 +333,38 @@ impl Type {
         )
     }
 
-    fn try_map_external_type(_type_name: &str) -> Option<OutputType> {
-        // TODO: Handle types from other packages with Rust bindings here (e.g. NumPy)
-        None
+    fn try_map_external_type(type_name: &str) -> Option<OutputType> {
+        // TODO: Handle types from other packages with Rust bindings here
+        match type_name {
+            #[cfg(feature = "numpy")]
+            numpy_ndarray
+                if numpy_ndarray
+                    .split_once('[')
+                    .map(|s| s.0)
+                    .unwrap_or(numpy_ndarray)
+                    .split('.')
+                    .last()
+                    .unwrap_or(numpy_ndarray)
+                    .to_lowercase()
+                    == "ndarray" =>
+            {
+                Some(OutputType::new(
+                    quote!(
+                        ::pyo3::Bound<
+                            'py,
+                            ::numpy::PyArray<::pyo3::Py<::pyo3::types::PyAny>, ::numpy::IxDyn>,
+                        >
+                    ),
+                    quote!(
+                        &::pyo3::Bound<
+                            'py,
+                            ::numpy::PyArray<::pyo3::Py<::pyo3::types::PyAny>, ::numpy::IxDyn>,
+                        >
+                    ),
+                ))
+            }
+            _ => None,
+        }
     }
 }