view rust/hg-cpython/src/conversion.rs @ 51686:39033e7a6e0a

convert: stringify `shlex` class argument

The documentation is handwavy, but typeshed says this should be `str`[1].  I'm
not sure if this is the correct encoding (vs `fsencode` or "latin1" like the
tokens returned by the proxy class).

While we're here, we can add a few more type hints that would have caused pytype
to flag the problem.

[1] https://github.com/python/typeshed/blob/6a9b53e719a139c2d6b41cf265ed0990cf438192/stdlib/shlex.pyi#L51

// 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, PyErr, PyObject, PyResult, Python};
use hg::{Revision, RevlogIndex, UncheckedRevision};

use crate::{exceptions::GraphError, PyRevision};

/// 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, I>(
    py: Python,
    revs: &PyObject,
    index: &I,
) -> PyResult<C>
where
    C: FromIterator<Revision>,
    I: RevlogIndex,
{
    rev_pyiter_collect_or_else(py, revs, index, |r| {
        PyErr::new::<GraphError, _>(py, ("InvalidRevision", r.0))
    })
}

/// Same as [`rev_pyiter_collect`], giving control on returned errors
pub fn rev_pyiter_collect_or_else<C, I>(
    py: Python,
    revs: &PyObject,
    index: &I,
    invalid_rev_error: impl FnOnce(PyRevision) -> PyErr + Copy,
) -> PyResult<C>
where
    C: FromIterator<Revision>,
    I: RevlogIndex,
{
    revs.iter(py)?
        .map(|r| {
            r.and_then(|o| match o.extract::<PyRevision>(py) {
                Ok(r) => index
                    .check_revision(UncheckedRevision(r.0))
                    .ok_or_else(|| invalid_rev_error(r)),
                Err(e) => Err(e),
            })
        })
        .collect()
}