Rename the base option in the pyclass macro to extends

"extends" is intuitive for people with java or ES6 experience, and it also aligns pyo3 with
wasm-bindgen (see rustwasm/rfcs#2)

Author: konstin

CHANGELOG.md

@@ -5,6 +5,7 @@
 * Upgraded to syn 0.14 which means much better error messages :tada:
 * 128 bit integer support by [kngwyu](https://github.com/kngwyu) ([#137](https://github.com/PyO3/pyo3/pull/173))
 * Added `py` prefixes to the proc macros and moved them into the root module. You should just use the plain proc macros, i.e. `#[pyclass]`, `#[pymethods]`, `#[pyproto]`, `#[pyfunction]` and `#[pymodinit]`. This is important because `proc_macro_path_invoc` isn't going to be stabilized soon.
+* Renamed the `base` option in the `pyclass` macro to `extends`.
 * `#[pymodinit]` uses the function name as module name, unless the name is overrriden with `#[pymodinit(name)]`
 * The guide is now properly versioned.
 * A few internal macros became part of the public api ([#155](https://github.com/PyO3/pyo3/pull/155), [#186](https://github.com/PyO3/pyo3/pull/186))

guide/src/class.md

@@ -33,7 +33,7 @@ so that they can benefit from a freelist. `XXX` is a number of items for free li
 participate in python garbage collector. If a custom class contains references to other
 python object that can be collected, the `PyGCProtocol` trait has to be implemented.
 * `weakref` - adds support for python weak references
-* `base=BaseType` - use a custom base class. The base BaseType must implement `PyTypeInfo`.
+* `extends=BaseType` - use a custom base class. The base BaseType must implement `PyTypeInfo`.
 * `subclass` - Allows Python classes to inherit from this class
 * `dict` - adds `__dict__` support, the instances of this type have a dictionary containing instance variables. (Incomplete, see [#123](https://github.com/PyO3/pyo3/issues/123))
 
@@ -115,7 +115,7 @@ impl BaseClass {
    }
 }
 
-#[pyclass(base=BaseClass)]
+#[pyclass(extends=BaseClass)]
 struct SubClass {
    val2: usize,
    token: PyToken,

pyo3-derive-backend/src/args.rs

@@ -180,6 +180,7 @@ mod test {
 
     use args::{parse_arguments, Argument};
     use syn;
+    use proc_macro::TokenStream;
 
     fn items(s: TokenStream) -> Vec<syn::NestedMeta> {
         let dummy: syn::ItemFn = parse_quote!{#s fn dummy() {}};

pyo3-derive-backend/src/module.rs

@@ -17,11 +17,10 @@ pub fn py3_init(fnname: &syn::Ident, name: &syn::Ident, doc: syn::Lit) -> TokenS
     quote! {
         #[no_mangle]
         #[allow(non_snake_case)]
+        #[doc(hidden)]
         /// This autogenerated function is called by the python interpreter when importing
         /// the module.
         pub unsafe extern "C" fn #cb_name() -> *mut ::pyo3::ffi::PyObject {
-            use ::pyo3::{IntoPyPointer, ObjectProtocol};
-
             ::pyo3::init_once();
 
             static mut MODULE_DEF: ::pyo3::ffi::PyModuleDef = ::pyo3::ffi::PyModuleDef_INIT;
@@ -48,7 +47,7 @@ pub fn py3_init(fnname: &syn::Ident, name: &syn::Ident, doc: syn::Lit) -> TokenS
             };
             _module.add("__doc__", #doc).expect("Failed to add doc for module");
             match #fnname(_py, _module) {
-                Ok(_) => _module.into_ptr(),
+                Ok(_) => ::pyo3::IntoPyPointer::into_ptr(_module),
                 Err(e) => {
                     e.restore(_py);
                     ::std::ptr::null_mut()

pyo3-derive-backend/src/py_class.rs

@@ -445,7 +445,7 @@ fn parse_attribute(
                         }
                         _ => println!("Wrong 'name' format: {:?}", *ass.right),
                     },
-                    "base" => match *ass.right {
+                    "extends" => match *ass.right {
                         syn::Expr::Path(ref exp) => {
                             base = syn::TypePath {
                                 path: exp.path.clone(),

tests/test_gc.rs

@@ -231,7 +231,7 @@ impl Drop for BaseClassWithDrop {
     }
 }
 
-#[pyclass(base=BaseClassWithDrop)]
+#[pyclass(extends=BaseClassWithDrop)]
 struct SubClassWithDrop {
     token: PyToken,
     data: Option<Arc<AtomicBool>>,

tests/test_inheritance.rs

@@ -43,7 +43,7 @@ impl BaseClass {
     }
 }
 
-#[pyclass(base=BaseClass)]
+#[pyclass(extends=BaseClass)]
 struct SubClass {
     #[prop(get)]
     val2: usize,