rust/hg-cpython/src/conversion.rs

commit: move the addremove logic around to make the next changeset clearer

Lets do the noise now, without changing any thing. So the new changeset can
focus on the actual semantic changes.

// conversion.rs
//
// Copyright 2019 Georges Racinet <[e-mail]>
//
// 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;

/// 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()
}