Mercurial > hg
diff rust/hg-cpython/src/conversion.rs @ 50979:4c5f6e95df84
rust: make `Revision` a newtype
This change is the one we've been building towards during this series.
The aim is to make `Revision` mean more than a simple integer, holding
the information that it is valid for a given revlog index.
While this still allows for programmer error, since creating a revision
directly and querying a different index with a "checked" revision are
still possible, the friction created by the newtype will hopefully make
us think twice about which type to use.
Enough of the Rust ecosystem relies on the newtype pattern to be
efficiently optimized away (even compiler in codegen testsĀ¹), so I'm not
worried about this being a fundamental problem.
[1] https://github.com/rust-lang/rust/blob/7a70647f195f6b0a0f1ebd72b1542ba91a32f43a/tests/codegen/vec-in-place.rs#L47
author | Raphaël Gomès <rgomes@octobus.net> |
---|---|
date | Fri, 18 Aug 2023 14:34:29 +0200 |
parents | c7fb9b74e753 |
children | 5a7d5fd6808c |
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--- a/rust/hg-cpython/src/conversion.rs Thu Aug 10 11:01:07 2023 +0200 +++ b/rust/hg-cpython/src/conversion.rs Fri Aug 18 14:34:29 2023 +0200 @@ -8,8 +8,10 @@ //! 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 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 /// @@ -17,11 +19,28 @@ /// 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> +pub fn rev_pyiter_collect<C, I>( + py: Python, + revs: &PyObject, + index: &I, +) -> PyResult<C> where C: FromIterator<Revision>, + I: RevlogIndex, { revs.iter(py)? - .map(|r| r.and_then(|o| o.extract::<Revision>(py))) + .map(|r| { + r.and_then(|o| match o.extract::<PyRevision>(py) { + Ok(r) => index + .check_revision(UncheckedRevision(r.0)) + .ok_or_else(|| { + PyErr::new::<GraphError, _>( + py, + ("InvalidRevision", r.0), + ) + }), + Err(e) => Err(e), + }) + }) .collect() }