34 releases (13 breaking)
0.17.0 | Oct 19, 2022 |
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0.16.0-rkyv.3 | Jun 8, 2022 |
0.15.0-rc.1 | Feb 24, 2022 |
0.12.0-rc.5 |
|
0.5.3 | Nov 17, 2020 |
#527 in Data structures
158 downloads per month
Used in 5 crates
(4 directly)
34KB
801 lines
microkelvin
Crate for creating and traversing recursively annotated structures.
Compound trait
/// A type that can recursively contain itself and leaves.
pub trait Compound<A>: Sized {
/// The leaf type of the compound collection
type Leaf;
/// Returns a reference to a possible child at specified index
fn child(&self, index: usize) -> Child<Self, A>;
/// Returns a mutable reference to a possible child at specified index
fn child_mut(&mut self, index: usize) -> ChildMut<Self, A>;
}
The Compound
trait defines a type as a collection type. This means that it
can be searched and have branches constructed pointing to its elements.
Branch walking
The Walker
trait can be implemented for walking the tree in a user defined
way. As an example, here's AllLeaves
- an implementation used internally:
/// Walker that visits all leaves
pub struct AllLeaves;
impl<C, A> Walker<C, A> for AllLeaves
where
C: Compound<A>,
{
fn walk(&mut self, walk: Walk<C, A>) -> Step {
for i in 0.. {
match walk.child(i) {
Child::Leaf(_) => return Step::Found(i),
Child::Node(_) => return Step::Into(i),
Child::Empty => (),
Child::EndOfNode => return Step::Advance,
}
}
unreachable!()
}
}
Usage
Please check out the nstack implementation of a stack/vector type for a more advanced example.
Dependencies
~10KB