rust-cpython: remove useless Option<$leaked> from py_shared_iterator
We no longer need to carefully drop the iterator when it's consumed. Mutation
is allowed even if the iterator exists.
There's a minor behavior change: next(iter) may return/raise something other
than StopIteration if it's called after the iterator has been fully consumed,
and if the Rust object isn't a FusedIterator.
// conversion.rs
//
// Copyright 2019 Georges Racinet <georges.racinet@octobus.net>
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2 or any later version.
//! Bindings for the hg::ancestors module provided by the
//! `hg-core` crate. From Python, this will be seen as `rustext.ancestor`
use cpython::{ObjectProtocol, PyObject, PyResult, Python};
use hg::Revision;
use std::iter::FromIterator;
/// Utility function to convert a Python iterable into various collections
///
/// We need this in particular to feed to various methods of inner objects
/// with `impl IntoIterator<Item=Revision>` arguments, because
/// a `PyErr` can arise at each step of iteration, whereas these methods
/// expect iterables over `Revision`, not over some `Result<Revision, PyErr>`
pub fn rev_pyiter_collect<C>(py: Python, revs: &PyObject) -> PyResult<C>
where
C: FromIterator<Revision>,
{
revs.iter(py)?
.map(|r| r.and_then(|o| o.extract::<Revision>(py)))
.collect()
}