comparison rust/hg-cpython/src/ref_sharing.rs @ 42888:67853749961b

rust-cpython: replace dyn Iterator<..> of mapping with concrete type

See the previous commit for why. The docstring is moved accordingly.

42887:706104dcb2c8

/// * `$inner_struct` is the identifier of the underlying Rust struct
/// * `$data_member` is the identifier of the data member of `$inner_struct`
/// that will be shared.
/// * `$leaked` is the identifier to give to the struct that will manage
/// references to `$name`, to be used for example in other macros like
/// `py_shared_mapping_iterator`.
///
/// # Example
///
/// ```
/// struct MyStruct {

        }
    };
}

/// Defines a `py_class!` that acts as a Python iterator over a Rust iterator.
macro_rules! py_shared_iterator_impl {
    (
        $name: ident,
        $leaked: ident,
        $iterator_type: ty,

                )
            }
        }
    };
}

/// Defines a `py_class!` that acts as a Python mapping iterator over a Rust
/// iterator.
///
/// TODO: this is a bit awkward to use, and a better (more complicated)
///     procedural macro would simplify the interface a lot.
///
/// # Parameters
///
/// * `$name` is the identifier to give to the resulting Rust struct.
/// * `$leaked` corresponds to `$leaked` in the matching `py_shared_ref!` call.
/// * `$key_type` is the type of the key in the mapping
/// * `$value_type` is the type of the value in the mapping
/// * `$success_func` is a function for processing the Rust `(key, value)`
/// tuple on iteration success, turning it into something Python understands.
/// * `$success_func` is the return type of `$success_func`
///
/// # Example
///
/// ```
/// struct MyStruct {
///     inner: HashMap<Vec<u8>, Vec<u8>>;
/// }
///
/// py_class!(pub class MyType |py| {
///     data inner: PySharedRefCell<MyStruct>;
///     data py_shared_state: PySharedState;
///
///     def __iter__(&self) -> PyResult<MyTypeItemsIterator> {
///         let (leak_handle, leaked_ref) = unsafe { self.leak_immutable(py)? };
///         MyTypeItemsIterator::create_instance(
///             py,
///             RefCell::new(Some(leak_handle)),
///             RefCell::new(leaked_ref.iter()),
///         )
///     }
/// });
///
/// impl MyType {
///     fn translate_key_value(
///         py: Python,
///         res: (&Vec<u8>, &Vec<u8>),
///     ) -> PyResult<Option<(PyBytes, PyBytes)>> {
///         let (f, entry) = res;
///         Ok(Some((
///             PyBytes::new(py, f),
///             PyBytes::new(py, entry),
///         )))
///     }
/// }
///
/// py_shared_ref!(MyType, MyStruct, inner, MyTypeLeakedRef);
///
/// py_shared_mapping_iterator!(
///     MyTypeItemsIterator,
///     MyTypeLeakedRef,
///     Vec<u8>,
///     Vec<u8>,
///     MyType::translate_key_value,
///     Option<(PyBytes, PyBytes)>
/// );
/// ```
#[allow(unused)] // Removed in a future patch
macro_rules! py_shared_mapping_iterator {
    (
        $name:ident,
        $leaked:ident,
        $key_type: ty,
        $value_type: ty,
        $success_func: path,
        $success_type: ty
    ) => {
        py_shared_iterator_impl!(
            $name,
            $leaked,
            Box<
                dyn Iterator<Item = (&'static $key_type, &'static $value_type)>
                    + Send,
            >,
            $success_func,
            $success_type
        );
    };
}

42888:67853749961b

/// * `$inner_struct` is the identifier of the underlying Rust struct
/// * `$data_member` is the identifier of the data member of `$inner_struct`
/// that will be shared.
/// * `$leaked` is the identifier to give to the struct that will manage
/// references to `$name`, to be used for example in other macros like
/// `py_shared_iterator_impl`.
///
/// # Example
///
/// ```
/// struct MyStruct {

        }
    };
}

/// Defines a `py_class!` that acts as a Python iterator over a Rust iterator.
///
/// TODO: this is a bit awkward to use, and a better (more complicated)
///     procedural macro would simplify the interface a lot.
///
/// # Parameters
///
/// * `$name` is the identifier to give to the resulting Rust struct.
/// * `$leaked` corresponds to `$leaked` in the matching `py_shared_ref!` call.
/// * `$iterator_type` is the type of the Rust iterator.
/// * `$success_func` is a function for processing the Rust `(key, value)`
/// tuple on iteration success, turning it into something Python understands.
/// * `$success_func` is the return type of `$success_func`
///
/// # Example
///
/// ```
/// struct MyStruct {
///     inner: HashMap<Vec<u8>, Vec<u8>>;
/// }
///
/// py_class!(pub class MyType |py| {
///     data inner: PySharedRefCell<MyStruct>;
///     data py_shared_state: PySharedState;
///
///     def __iter__(&self) -> PyResult<MyTypeItemsIterator> {
///         let (leak_handle, leaked_ref) = unsafe { self.leak_immutable(py)? };
///         MyTypeItemsIterator::create_instance(
///             py,
///             RefCell::new(Some(leak_handle)),
///             RefCell::new(leaked_ref.iter()),
///         )
///     }
/// });
///
/// impl MyType {
///     fn translate_key_value(
///         py: Python,
///         res: (&Vec<u8>, &Vec<u8>),
///     ) -> PyResult<Option<(PyBytes, PyBytes)>> {
///         let (f, entry) = res;
///         Ok(Some((
///             PyBytes::new(py, f),
///             PyBytes::new(py, entry),
///         )))
///     }
/// }
///
/// py_shared_ref!(MyType, MyStruct, inner, MyTypeLeakedRef);
///
/// py_shared_iterator_impl!(
///     MyTypeItemsIterator,
///     MyTypeLeakedRef,
///     HashMap<'static, Vec<u8>, Vec<u8>>,
///     MyType::translate_key_value,
///     Option<(PyBytes, PyBytes)>
/// );
/// ```
macro_rules! py_shared_iterator_impl {
    (
        $name: ident,
        $leaked: ident,
        $iterator_type: ty,

                )
            }
        }
    };
}