rust-format: cleanup ancestors.rs to make rustfmt happy

Differential Revision: https://phab.mercurial-scm.org/D8224

rust/hg-cpython/src/ancestors.rs

@@ -1,222 +1,227 b''
 // ancestors.rs
 //
 // Copyright 2018 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`
 //! and can be used as replacement for the the pure `ancestor` Python module.
 //!
 //! # Classes visible from Python:
 //! - [`LazyAncestors`] is the Rust implementation of
 //!   `mercurial.ancestor.lazyancestors`. The only difference is that it is
 //!   instantiated with a C `parsers.index` instance instead of a parents
 //!   function.
 //!
 //! - [`MissingAncestors`] is the Rust implementation of
 //!   `mercurial.ancestor.incrementalmissingancestors`.
 //!
 //!   API differences:
 //!    + it is instantiated with a C `parsers.index`
 //!      instance instead of a parents function.
 //!    + `MissingAncestors.bases` is a method returning a tuple instead of
 //!      a set-valued attribute. We could return a Python set easily if our
 //!      [PySet PR](https://github.com/dgrunwald/rust-cpython/pull/165)
 //!      is accepted.
 //!
 //! - [`AncestorsIterator`] is the Rust counterpart of the
 //!   `ancestor._lazyancestorsiter` Python generator. From Python, instances of
 //!   this should be mainly obtained by calling `iter()` on a [`LazyAncestors`]
 //!   instance.
 //!
 //! [`LazyAncestors`]: struct.LazyAncestors.html
 //! [`MissingAncestors`]: struct.MissingAncestors.html
 //! [`AncestorsIterator`]: struct.AncestorsIterator.html
 use crate::revlog::pyindex_to_graph;
 use crate::{
     cindex::Index, conversion::rev_pyiter_collect, exceptions::GraphError,
 };
 use cpython::{
     ObjectProtocol, PyClone, PyDict, PyList, PyModule, PyObject, PyResult,
     Python, PythonObject, ToPyObject,
 };
 use hg::Revision;
 use hg::{
     AncestorsIterator as CoreIterator, LazyAncestors as CoreLazy,
     MissingAncestors as CoreMissing,
 };
 use std::cell::RefCell;
 use std::collections::HashSet;
 
 py_class!(pub class AncestorsIterator |py| {
     data inner: RefCell<Box<CoreIterator<Index>>>;
 
     def __next__(&self) -> PyResult<Option<Revision>> {
         match self.inner(py).borrow_mut().next() {
             Some(Err(e)) => Err(GraphError::pynew(py, e)),
             None => Ok(None),
             Some(Ok(r)) => Ok(Some(r)),
         }
     }
 
     def __contains__(&self, rev: Revision) -> PyResult<bool> {
         self.inner(py).borrow_mut().contains(rev)
             .map_err(|e| GraphError::pynew(py, e))
     }
 
     def __iter__(&self) -> PyResult<Self> {
         Ok(self.clone_ref(py))
     }
 
     def __new__(_cls, index: PyObject, initrevs: PyObject, stoprev: Revision,
                 inclusive: bool) -> PyResult<AncestorsIterator> {
         let initvec: Vec<Revision> = rev_pyiter_collect(py, &initrevs)?;
         let ait = CoreIterator::new(
             pyindex_to_graph(py, index)?,
             initvec,
             stoprev,
             inclusive,
         )
         .map_err(|e| GraphError::pynew(py, e))?;
         AncestorsIterator::from_inner(py, ait)
     }
 
 });
 
 impl AncestorsIterator {
     pub fn from_inner(py: Python, ait: CoreIterator<Index>) -> PyResult<Self> {
         Self::create_instance(py, RefCell::new(Box::new(ait)))
     }
 }
 
 py_class!(pub class LazyAncestors |py| {
     data inner: RefCell<Box<CoreLazy<Index>>>;
 
     def __contains__(&self, rev: Revision) -> PyResult<bool> {
         self.inner(py)
             .borrow_mut()
             .contains(rev)
             .map_err(|e| GraphError::pynew(py, e))
     }
 
     def __iter__(&self) -> PyResult<AncestorsIterator> {
         AncestorsIterator::from_inner(py, self.inner(py).borrow().iter())
     }
 
     def __bool__(&self) -> PyResult<bool> {
         Ok(!self.inner(py).borrow().is_empty())
     }
 
     def __new__(_cls, index: PyObject, initrevs: PyObject, stoprev: Revision,
                 inclusive: bool) -> PyResult<Self> {
         let initvec: Vec<Revision> = rev_pyiter_collect(py, &initrevs)?;
 
         let lazy =
             CoreLazy::new(pyindex_to_graph(py, index)?,
                           initvec, stoprev, inclusive)
                 .map_err(|e| GraphError::pynew(py, e))?;
 
         Self::create_instance(py, RefCell::new(Box::new(lazy)))
         }
 
 });
 
 py_class!(pub class MissingAncestors |py| {
     data inner: RefCell<Box<CoreMissing<Index>>>;
 
-    def __new__(_cls, index: PyObject, bases: PyObject) -> PyResult<MissingAncestors> {
+    def __new__(
+        _cls,
+        index: PyObject,
+        bases: PyObject
+    )
+    -> PyResult<MissingAncestors> {
         let bases_vec: Vec<Revision> = rev_pyiter_collect(py, &bases)?;
         let inner = CoreMissing::new(pyindex_to_graph(py, index)?, bases_vec);
         MissingAncestors::create_instance(py, RefCell::new(Box::new(inner)))
     }
 
     def hasbases(&self) -> PyResult<bool> {
         Ok(self.inner(py).borrow().has_bases())
     }
 
     def addbases(&self, bases: PyObject) -> PyResult<PyObject> {
         let mut inner = self.inner(py).borrow_mut();
         let bases_vec: Vec<Revision> = rev_pyiter_collect(py, &bases)?;
         inner.add_bases(bases_vec);
         // cpython doc has examples with PyResult<()> but this gives me
         //   the trait `cpython::ToPyObject` is not implemented for `()`
         // so let's return an explicit None
         Ok(py.None())
     }
 
     def bases(&self) -> PyResult<HashSet<Revision>> {
         Ok(self.inner(py).borrow().get_bases().clone())
     }
 
     def basesheads(&self) -> PyResult<HashSet<Revision>> {
         let inner = self.inner(py).borrow();
         inner.bases_heads().map_err(|e| GraphError::pynew(py, e))
     }
 
     def removeancestorsfrom(&self, revs: PyObject) -> PyResult<PyObject> {
         let mut inner = self.inner(py).borrow_mut();
         // this is very lame: we convert to a Rust set, update it in place
         // and then convert back to Python, only to have Python remove the
         // excess (thankfully, Python is happy with a list or even an iterator)
         // Leads to improve this:
         //  - have the CoreMissing instead do something emit revisions to
         //    discard
         //  - define a trait for sets of revisions in the core and implement
         //    it for a Python set rewrapped with the GIL marker
         let mut revs_pyset: HashSet<Revision> = rev_pyiter_collect(py, &revs)?;
         inner.remove_ancestors_from(&mut revs_pyset)
             .map_err(|e| GraphError::pynew(py, e))?;
 
         // convert as Python list
         let mut remaining_pyint_vec: Vec<PyObject> = Vec::with_capacity(
             revs_pyset.len());
         for rev in revs_pyset {
             remaining_pyint_vec.push(rev.to_py_object(py).into_object());
         }
         let remaining_pylist = PyList::new(py, remaining_pyint_vec.as_slice());
         revs.call_method(py, "intersection_update", (remaining_pylist, ), None)
     }
 
     def missingancestors(&self, revs: PyObject) -> PyResult<PyList> {
         let mut inner = self.inner(py).borrow_mut();
         let revs_vec: Vec<Revision> = rev_pyiter_collect(py, &revs)?;
         let missing_vec = match inner.missing_ancestors(revs_vec) {
             Ok(missing) => missing,
             Err(e) => {
                 return Err(GraphError::pynew(py, e));
             }
         };
         // convert as Python list
         let mut missing_pyint_vec: Vec<PyObject> = Vec::with_capacity(
             missing_vec.len());
         for rev in missing_vec {
             missing_pyint_vec.push(rev.to_py_object(py).into_object());
         }
         Ok(PyList::new(py, missing_pyint_vec.as_slice()))
     }
 });
 
 /// Create the module, with __package__ given from parent
 pub fn init_module(py: Python, package: &str) -> PyResult<PyModule> {
     let dotted_name = &format!("{}.ancestor", package);
     let m = PyModule::new(py, dotted_name)?;
     m.add(py, "__package__", package)?;
     m.add(
         py,
         "__doc__",
         "Generic DAG ancestor algorithms - Rust implementation",
     )?;
     m.add_class::<AncestorsIterator>(py)?;
     m.add_class::<LazyAncestors>(py)?;
     m.add_class::<MissingAncestors>(py)?;
 
     let sys = PyModule::import(py, "sys")?;
     let sys_modules: PyDict = sys.get(py, "modules")?.extract(py)?;
     sys_modules.set_item(py, dotted_name, &m)?;
     // Example C code (see pyexpat.c and import.c) will "give away the
     // reference", but we won't because it will be consumed once the
     // Rust PyObject is dropped.
     Ok(m)
 }