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//! Implementation of a Nested Containment List. //! //! A Nested Containment List is a data structure for storing types that implement the //! [`core::ops::RangeBounds`] trait. Elements stored in a [`NestedContainmentList`] are stored in a //! nested structure to allow for easy querying using other `RangeBounds` queries. //! //! ## Construction //! //! Construction of [`NestedContainmentList`]s can be done using either the [`new()`] or //! [`from_iter()`] methods. Construction from `from_iter()` has temporal complexity //! *O(n log(n))*, where *n* is the length of the slice. //! //! ``` //! use nested_containment_list::NestedContainmentList; //! use std::ops::Range; //! //! let nclist = NestedContainmentList::<Range<usize>, usize>::new(); //! ``` //! //! ``` //! use nested_containment_list::NestedContainmentList; //! use std::iter::FromIterator; //! //! let nclist = NestedContainmentList::from_iter(vec![1..5, 2..4, 5..7]); //! ``` //! //! ## Mutation //! //! A [`NestedContainmentList`] allows for insertion and removal of [`RangeBounds`] types. Both of //! these methods have a temporal complexity of *O(log(n))*, where *n* is the number of //! `RangeBounds` stored in the data structure. //! //! ``` //! use nested_containment_list::NestedContainmentList; //! //! let mut nclist = NestedContainmentList::new(); //! //! nclist.insert(1..5); //! nclist.remove(&(1..5)); //! ``` //! //! ## Iteration //! //! Iterating over a [`NestedContainmentList`] is done in a nested manner. An [`Iterator`] is //! obtained from the [`overlapping()`] method. It is used to iterate directly over the top-most //! sublist, returning values which overlap with the query range, with nested intervals contained //! within the top-most elements being accessed through nested sublists. //! //! For example, iterating over all elements can be done as follows: //! //! ``` //! use nested_containment_list::NestedContainmentList; //! use std::iter::FromIterator; //! //! let nclist = NestedContainmentList::from_iter(vec![1..5, 2..4, 6..7]); //! let mut sublist = nclist.overlapping(&(..)); //! //! // The first element in the top-most sublist, 1..5. //! let first_element = sublist.next().unwrap(); //! assert_eq!(first_element.value, &(1..5)); //! //! // Contained inside the element's sublist is the interval 2..4. //! assert_eq!(first_element.sublist().next().unwrap().value, &(2..4)); //! //! // The next element in the top-most sublist is 6..7, so it is obtained like the first element. //! let second_element = sublist.next().unwrap(); //! assert_eq!(second_element.value, &(6..7)); //! ``` //! //! To remove a single level of nesting, one may use the [`Iterator::flatten()`] method. //! //! # no_std //! This crate is usable in //! [`no_std`](https://doc.rust-lang.org/1.7.0/book/using-rust-without-the-standard-library.html) //! environments when compiled on stable `rustc 1.36.0` or higher. The version limitation is due to //! the use of [`alloc`](https://doc.rust-lang.org/alloc/index.html), allowing for heap allocation //! without use of [`std`](https://doc.rust-lang.org/std/). //! //! [`from_iter()`]: NestedContainmentList::from_iter() //! [`new()`]: NestedContainmentList::new() //! [`overlapping()`]: NestedContainmentList::overlapping() //! [`Iterator`]: core::iter::Iterator //! [`Iterator::flatten()`]: core::iter::Iterator::flatten() //! [`RangeBounds`]: core::ops::RangeBounds #![warn(clippy::cargo, clippy::nursery, clippy::pedantic)] #![allow(clippy::doc_markdown, clippy::redundant_pub_crate)] #![cfg_attr(rustc_1_36, no_std)] #[cfg(rustc_1_36)] extern crate alloc; #[cfg(not(rustc_1_36))] extern crate std as alloc; #[cfg(not(rustc_1_36))] extern crate std as core; #[cfg(test)] #[macro_use] extern crate claim; #[cfg(test)] extern crate more_ranges; mod nestable; use alloc::vec::Vec; use core::{ borrow::Borrow, cmp::Ordering, iter::{once, Chain, FromIterator, FusedIterator, Iterator, Once}, marker::PhantomData, mem, ops::RangeBounds, }; use nestable::Nestable; /// Internal element, stored within the `NestedContainmentList` and its associated `Iterators`. /// /// The values in here are more directly used in the external API's `OverlappingElement` and /// `IterElement` types. #[derive(Debug)] struct Element<R, T> where R: RangeBounds<T>, T: Ord, { value: R, sublist_len: usize, _marker: PhantomData<T>, } /// An element contained within an [`Overlapping`]. /// /// This element allows access to its contained value `I` and its sub-elements which also overlap /// with the query `S`. /// /// An `OverlappingElement` is usually obtained from iterating over an `Overlapping`. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..4, 2..3]); /// let query = 2..4; /// let mut overlapping = nclist.overlapping(&query); /// /// let overlapping_element = overlapping.next().unwrap(); /// assert_eq!(overlapping_element.value, &(1..4)); /// /// let inner_overlapping_element = overlapping_element.sublist().next().unwrap(); /// assert_eq!(inner_overlapping_element.value, &(2..3)); /// ``` #[derive(Debug)] pub struct OverlappingElement<'a, R, S, T> where R: RangeBounds<T> + 'a, S: RangeBounds<T> + 'a, T: Ord + 'a, { pub value: &'a R, sublist_elements: &'a [Element<R, T>], query: &'a S, _marker: PhantomData<T>, } impl<'a, R, S, T> OverlappingElement<'a, R, S, T> where R: RangeBounds<T>, S: RangeBounds<T>, T: Ord, { /// Return an [`Overlapping`] [`Iterator`] over this element's contained sublist. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..5, 2..3, 3..4]); /// let query = 2..4; /// let mut overlapping = nclist.overlapping(&query); /// /// let overlapping_element = overlapping.next().unwrap(); /// assert_eq!(overlapping_element.value, &(1..5)); /// /// let mut inner_overlapping = overlapping_element.sublist(); /// assert_eq!(inner_overlapping.next().unwrap().value, &(2..3)); /// assert_eq!(inner_overlapping.next().unwrap().value, &(3..4)); /// ``` /// /// [`Iterator`]: core::iter::Iterator #[must_use] pub fn sublist(&self) -> Overlapping<'a, R, S, T> { Overlapping::new(self.sublist_elements, self.query) } } impl<'a, R, S, T> IntoIterator for OverlappingElement<'a, R, S, T> where R: RangeBounds<T>, S: RangeBounds<T>, T: Ord, { type Item = Self; type IntoIter = Chain<Once<Self::Item>, Overlapping<'a, R, S, T>>; /// Returns an [`Iterator`] over this element's `value`, followed by its `sublist()` elements /// that overlap with the query `S`. /// /// This is useful if you want to iterate over all values including the enclosing value. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..4, 2..3]); /// let mut overlapping = nclist.overlapping(&(2..5)); /// let first_element = overlapping.next().unwrap(); /// let mut first_element_iter = first_element.into_iter(); /// /// assert_eq!(first_element_iter.next().unwrap().value, &(1..4)); /// assert_eq!(first_element_iter.next().unwrap().value, &(2..3)); /// ``` /// /// [`Iterator`]: core::iter::Iterator #[must_use] fn into_iter(self) -> Self::IntoIter { once(Self { value: self.value, sublist_elements: &[], query: self.query, _marker: PhantomData, }) .chain(self.sublist()) } } /// An [`Iterator`] over elements in a [`NestedContainmentList`] that overlap a query. /// /// This [`Iterator`] is typically created from the [`NestedContainmentList::overlapping()`] method. /// /// Iterates over all elements within the [`NestedContainmentList`] that overlap with the query /// interval. These elements are iterated in a nested structure, with all elements contained in /// other elements being accessed through those elements' [`sublist()`] methods. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..5, 2..3, 2..4, 5..7]); /// let query = 3..6; /// let mut overlapping = nclist.overlapping(&query); /// /// let first_element = overlapping.next().unwrap(); /// let second_element = overlapping.next().unwrap(); /// /// // The outermost elements are accessed directly. /// assert_eq!(first_element.value, &(1..5)); /// assert_eq!(second_element.value, &(5..7)); /// /// // Contained elements are accessed through their containing element's sublist. /// let mut inner_sublist = first_element.sublist(); /// let inner_element = inner_sublist.next().unwrap(); /// assert_eq!(inner_element.value, &(2..4)); /// /// // Note that 2..3 is not found within the nested iterators, since 2..3 does not overlap with 3..6. /// ``` /// /// [`sublist()`]: OverlappingElement::sublist() /// [`Iterator`]: core::iter::Iterator pub struct Overlapping<'a, R, S, T> where R: RangeBounds<T> + 'a, S: RangeBounds<T> + 'a, T: Ord + 'a, { index: usize, elements: &'a [Element<R, T>], query: &'a S, } impl<'a, R, S, T> Overlapping<'a, R, S, T> where R: RangeBounds<T>, S: RangeBounds<T>, T: Ord, { fn new(elements: &'a [Element<R, T>], query: &'a S) -> Self { // Find the index of the first overlapping interval in the top-most sublist. let mut index = 0; while index < elements.len() && !elements[index].value.overlapping(query) { index += elements[index].sublist_len + 1; } Overlapping { index, elements, query, } } } impl<'a, R, S, T> Iterator for Overlapping<'a, R, S, T> where R: RangeBounds<T>, S: RangeBounds<T>, T: Ord, { type Item = OverlappingElement<'a, R, S, T>; /// Returns the next outer-most element. /// /// Note that any values contained within a returned element must be accessed through the /// element's [`sublist()`] method. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..5]); /// let query = 2..3; /// let mut overlapping = nclist.overlapping(&query); /// /// assert_eq!(overlapping.next().unwrap().value, &(1..5)); /// assert!(overlapping.next().is_none()); /// ``` /// /// [`sublist()`]: OverlappingElement::sublist() fn next(&mut self) -> Option<Self::Item> { if self.index >= self.elements.len() { return None; } let current_index = self.index; // Next element. let element = &self.elements[self.index]; if element.value.overlapping(self.query) { // Skip over element's sublist. self.index += element.sublist_len + 1; Some(OverlappingElement { value: &element.value, sublist_elements: &self.elements[(current_index + 1)..self.index], query: self.query, _marker: PhantomData, }) } else { // End iteration, since there will be no more overlaps. self.index = self.elements.len(); None } } } impl<'a, R, S, T> FusedIterator for Overlapping<'a, R, S, T> where R: RangeBounds<T>, S: RangeBounds<T>, T: Ord, { } /// An element obtained from [`Iter`]. /// /// This element allows access to its `value`, as well as providing an `Iterator` over all values /// nested within `value` through the `sublist()` method. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..2]); /// /// let mut iter = nclist.into_iter(); /// assert_eq!(iter.next().unwrap().value, 1..2); /// ``` #[derive(Debug)] pub struct IterElement<R, T> where R: RangeBounds<T>, T: Ord, { pub value: R, sublist_elements: Vec<Element<R, T>>, } impl<R, T> IterElement<R, T> where R: RangeBounds<T>, T: Ord, { /// Returns an [`Iter`] [`Iterator`] over this element's sublist. /// /// Note that this method consumes the `IterElement`. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..4, 2..3]); /// /// let mut iter = nclist.into_iter(); /// let mut sublist = iter.next().unwrap().sublist(); /// assert_eq!(sublist.next().unwrap().value, 2..3); /// ``` /// /// [`Iterator`]: core::iter::Iterator pub fn sublist(self) -> Iter<R, T> { Iter { elements: self.sublist_elements, } } } impl<R, T> IntoIterator for IterElement<R, T> where R: RangeBounds<T>, T: Ord, { type Item = Self; type IntoIter = Chain<Once<Self::Item>, Iter<R, T>>; /// Returns an [`Iterator`] over this element's `value`, followed by its `sublist()`. /// /// This is useful if you want to iterate over all values including the enclosing value. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..4, 2..3]); /// let mut iter = nclist.into_iter(); /// let first_element = iter.next().unwrap(); /// let mut first_element_iter = first_element.into_iter(); /// /// assert_eq!(first_element_iter.next().unwrap().value, 1..4); /// assert_eq!(first_element_iter.next().unwrap().value, 2..3); /// ``` /// /// [`Iterator`]: core::iter::Iterator fn into_iter(self) -> Self::IntoIter { once(Self { value: self.value, sublist_elements: Vec::new(), }) .chain(Iter { elements: self.sublist_elements, }) } } /// An [`Iterator`] over all elements in a [`NestedContainmentList`]. /// /// This `Iterator` proceeds in a nested fashion, meaning it only yields the outer-most nested /// elements. To access the inner elements, call [`sublist()`] on the outer elements. /// /// # Example /// /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..2]); /// /// let mut iter = nclist.into_iter(); /// assert_eq!(iter.next().unwrap().value, 1..2); /// ``` /// /// [`Iterator`]: core::iter::Iterator /// [`sublist()`]: IterElement::sublist() pub struct Iter<R, T> where R: RangeBounds<T>, T: Ord, { elements: Vec<Element<R, T>>, } impl<R, T> Iterator for Iter<R, T> where R: RangeBounds<T>, T: Ord, { type Item = IterElement<R, T>; /// Yield the next outer-most element. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..2]); /// /// let mut iter = nclist.into_iter(); /// assert_eq!(iter.next().unwrap().value, 1..2); /// ``` fn next(&mut self) -> Option<Self::Item> { if self.elements.is_empty() { return None; } // TODO: Is there a more efficient way to do this without moving all elements left? // Perhaps reversing the Vec on creation? let element = self.elements.remove(0); let remaining_elements = self.elements.split_off(element.sublist_len); Some(IterElement { value: element.value, sublist_elements: mem::replace(&mut self.elements, remaining_elements), }) } } impl<R, T> FusedIterator for Iter<R, T> where R: RangeBounds<T>, T: Ord, { } /// Data structure for efficient storage and querying of [`RangeBounds`]. /// /// # Usage /// /// A `NestedContainmentList` is a collection of [`RangeBounds`], and can be used similar to other /// collections. It has a [`len()`] and a [`capacity()`], allows for mutation through [`insert()`] /// and [`remove()`]. A main difference between `NestedContainmentList` and other Rust collections /// is how its contents are accessed: they may be iterated over through [`overlapping()`]. For /// further details, see [Data Access](#data-access). /// /// ## Construction /// /// A `NestedContainmentList` stores [`RangeBounds`] in a nested structure to allow for fast querying. /// Construction of a `NestedContainmentList` has temporal complexity *O(n log(n))*, where *n* is /// the number of [`RangeBounds`] being stored. Both insertion and removal, with [`insert()`] and /// [`remove()`] respectively, into a `NestedContainmentList` has temporal complexity *O(log(n))*, /// where *n* is the number of [`RangeBounds`] currently stored. /// /// ### Example /// Construction of a `NestedContainmentList` can be done as follows: /// /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let mut nclist = NestedContainmentList::from_iter(vec![1..5, 2..4, 5..7]); /// ``` /// /// ## Data Access /// /// When data is stored within a `NestedContainmentList`, it is typically accessed by querying for /// [`RangeBounds`] overlapping another [`RangeBounds`], using the [`overlapping()`] method. /// /// Both methods return a nested [`Iterator`] structure, with the difference being that access /// through [`overlapping()`] only iterates over [`RangeBounds`] that overlap with the query /// value. For details on the [`Iterator`]s returned by these methods, see the documentation for /// [`Overlapping`]. /// /// Querying using [`overlapping()`] has temporal complexity *O(n + log(N))*, where *N* is the /// number of [`RangeBounds`] stored, and *n* is the number of intervals overlapping with the query /// value. /// /// ### Example /// Access using either method can be done as follows: /// /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let mut nclist = NestedContainmentList::from_iter(vec![1..5, 2..4, 5..7]); /// /// // Creates a Sublist Iterator. /// let mut sublist = nclist.overlapping(&(..)); /// /// // Creates an Overlapping Iterator. /// let query = 4..6; /// let mut overlapping = nclist.overlapping(&query); /// ``` /// /// [`capacity()`]: Self::capacity() /// [`insert()`]: Self::insert() /// [`len()`]: Self::len() /// [`overlapping()`]: Self::overlapping() /// [`remove()`]: Self::remove() /// [`Iterator`]: core::iter::Iterator /// [`RangeBounds`]: core::ops::RangeBounds #[derive(Debug)] pub struct NestedContainmentList<R, T> where R: RangeBounds<T>, T: Ord, { elements: Vec<Element<R, T>>, } impl<R, T> NestedContainmentList<R, T> where R: RangeBounds<T>, T: Ord, { /// Construct an empty `NestedContainmentList`. /// /// # Example /// The following example constructs a new `NestedContainmentList` to hold elements of type /// [`Range<usize>`]. /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::ops::Range; /// /// let nclist = NestedContainmentList::<Range<usize>, usize>::new(); /// ``` /// /// [`Range<usize>`]: core::ops::Range #[must_use] pub fn new() -> Self { Self { elements: Vec::new(), } } /// Construct an empty `NestedContainmentList` with the specified capacity. /// /// The `NestedContainmentList` will be able to hold exactly `capacity` [`RangeBounds`] without /// reallocating. If `capacity` is `0`, the `NestedContainmentList` will not allocate. /// /// Note that `capacity` is not the same as `len`. `len` is how many elements are actually /// contained, while `capacity` is how many could be contained given the current allocation. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// /// let mut nclist = NestedContainmentList::with_capacity(5); /// /// nclist.insert(1..2); // Does not reallocate, since capacity is available. /// ``` #[must_use] pub fn with_capacity(capacity: usize) -> Self { Self { elements: Vec::with_capacity(capacity), } } /// Returns the number of elements contained in the `NestedContainmentList`, also referred to as /// its 'length'. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// /// let mut nclist = NestedContainmentList::new(); /// assert_eq!(nclist.len(), 0); /// /// nclist.insert(1..5); /// assert_eq!(nclist.len(), 1); /// ``` #[must_use] pub fn len(&self) -> usize { self.elements.len() } /// Returns `true` if the `NestedContainmentList` contains no elements. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// /// let mut nclist = NestedContainmentList::new(); /// assert!(nclist.is_empty()); /// /// nclist.insert(1..5); /// assert!(!nclist.is_empty()); /// ``` #[must_use] pub fn is_empty(&self) -> bool { self.elements.is_empty() } /// Returns the number of elements the `NestedContainmentList` can hold without reallocating. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::ops::Range; /// /// let nclist = NestedContainmentList::<Range<usize>, usize>::with_capacity(10); /// assert_eq!(nclist.capacity(), 10); /// ``` #[must_use] pub fn capacity(&self) -> usize { self.elements.capacity() } /// Returns an [`Overlapping`] [`Iterator`] over all elements within the /// `NestedContainmentList`. /// /// The [`Overlapping`] is a nested [`Iterator`] over all values contained in the /// `NestedContainmentList` that overlap with the `query` [`RangeBounds`]. All [`RangeBounds`] /// contained within other [`RangeBounds`] in the collection that also overlap with the `query` /// are accessed as nested [`Overlapping`]s under their outer-most values. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..5, 2..3, 2..4, 5..7]); /// let query = 3..6; /// let mut overlapping = nclist.overlapping(&query); /// /// let first_element = overlapping.next().unwrap(); /// let second_element = overlapping.next().unwrap(); /// /// // The outermost elements are accessed directly. /// assert_eq!(first_element.value, &(1..5)); /// assert_eq!(second_element.value, &(5..7)); /// /// // Contained elements are accessed through their containing element's sublist. /// let mut inner_sublist = first_element.sublist(); /// let inner_element = inner_sublist.next().unwrap(); /// assert_eq!(inner_element.value, &(2..4)); /// /// // Note that 2..3 is not found within the nested iterators, since 2..3 does not overlap with 3..6. /// ``` /// /// [`Iterator`]: core::iter::Iterator #[must_use] pub fn overlapping<'a, S>(&'a self, query: &'a S) -> Overlapping<'a, R, S, T> where S: RangeBounds<T>, { Overlapping::new(&self.elements, query) } /// Insert a new value into the `NestedContainmentList`. /// /// This insertion preserves the internal nested structure of the container, and has temporal /// complexity of *O(log(n))*. /// /// If the `NestedContainmentList`'s `capacity` is not large enough, the `NestedContainmentList` /// will reallocate. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// /// let mut nclist = NestedContainmentList::new(); /// nclist.insert(1..2); /// ``` pub fn insert(&mut self, value: R) { // Direct insertion. let mut sublist_indices: Vec<usize> = Vec::with_capacity(self.elements.len()); let mut indices = 0..self.elements.len(); while let Some(index) = indices.next() { // If the value is ordered less than or equal to this element, then insert the value // before this element. match value.ordering(&self.elements[index].value) { Ordering::Less | Ordering::Equal => { // Find the length of the value's sublist. let mut len = 0; for inner_index in index..self.elements.len() { if Nestable::contains(&value, &self.elements[inner_index].value) { len += 1; } else { break; } } self.elements.insert( index, Element { value, sublist_len: len, _marker: PhantomData, }, ); // Lengthen the sublist of every parent element. for sublist_index in sublist_indices { self.elements[sublist_index].sublist_len += 1; } // The element is inserted. We are done. return; } _ => {} } let element = &self.elements[index]; if Nestable::contains(&element.value, &value) { // Proceed down this element's path. sublist_indices.push(index); } else { // If the value isn't contained in this element's sublist, we can skip it entirely. if element.sublist_len > 0 { indices.nth(element.sublist_len - 1); } } } // Since the value didn't belong somewhere in the middle, we must insert it at the end. self.elements.push(Element { value, sublist_len: 0, _marker: PhantomData, }); // Lengthen the sublist of every parent element. for sublist_index in sublist_indices { self.elements[sublist_index].sublist_len += 1; } } /// Remove the specified value from the `NestedContainmentList`. /// /// This removal preserves the internal nested structure of the container, and has temporal /// complexity *O(log(n))*. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let mut nclist = NestedContainmentList::from_iter(vec![1..5, 2..4, 3..4]); /// assert!(nclist.remove(&(2..4))); /// ``` pub fn remove<Q>(&mut self, value: &Q) -> bool where Q: RangeBounds<T>, R: Borrow<Q>, { // Direct removal. let mut sublist_indices: Vec<usize> = Vec::with_capacity(self.elements.len()); let mut indices = 0..self.elements.len(); while let Some(index) = indices.next() { match value.ordering(&self.elements[index].value) { // If the value is nestably equal to this element, remove it. Ordering::Equal => { self.elements.remove(index); // Shorten the sublist of every parent element. for sublist_index in sublist_indices { self.elements[sublist_index].sublist_len -= 1; } // The element is removed. We are done. return true; } // If the value is nestably less than this element, we have already passed where it // would be. Ordering::Less => { break; } Ordering::Greater => {} } let element = &self.elements[index]; if Nestable::contains(&element.value, value) { // Proceed down this element's path. sublist_indices.push(index); } else { // If the value isn't contained in this element's sublist, we can skip it entirely. if element.sublist_len > 0 { indices.nth(element.sublist_len - 1); } } } false } } impl<R, T> FromIterator<R> for NestedContainmentList<R, T> where R: RangeBounds<T>, T: Ord, { /// Construct a `NestedContainmentList` from an [`Iterator`]. /// /// This construction has temporal complexity of *O(n log(n))*, where *n* is the length of the /// `Iterator`. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::iter::FromIterator; /// /// let nclist = NestedContainmentList::from_iter(vec![1..5, 3..4, 2..4, 6..7]); /// ``` /// /// [`Iterator`]: core::iter::Iterator fn from_iter<I>(iter: I) -> Self where I: IntoIterator<Item = R>, { // Sort the elements. let mut values = iter.into_iter().collect::<Vec<_>>(); values.sort_unstable_by(Nestable::ordering); // Depth-first construction. let mut elements: Vec<Element<R, T>> = Vec::with_capacity(values.len()); let mut sublist_indices: Vec<usize> = Vec::with_capacity(values.len()); for index in 0..values.len() { let value = values.remove(0); while !sublist_indices.is_empty() { let sublist_index = sublist_indices.pop().unwrap(); if Nestable::contains(&elements[sublist_index].value, &value) { // We are within the previous sublist. sublist_indices.push(sublist_index); break; } else { // We are no longer within the previous sublist. let len = index - sublist_index - 1; elements[sublist_index].sublist_len = len; } } sublist_indices.push(index); elements.push(Element { value, sublist_len: 0, _marker: PhantomData, }); } // Clean up remaining sublist indices. for sublist_index in sublist_indices { let len = elements.len() - sublist_index - 1; elements[sublist_index].sublist_len = len; } Self { elements } } } impl<R, T> IntoIterator for NestedContainmentList<R, T> where R: RangeBounds<T>, T: Ord, { type Item = IterElement<R, T>; type IntoIter = Iter<R, T>; fn into_iter(self) -> Self::IntoIter { Iter { elements: self.elements, } } } impl<R, T> Default for NestedContainmentList<R, T> where R: RangeBounds<T>, T: Ord, { /// Constructs a new, empty `NestedContainmentList`. Equivalent to [`new()`]. /// /// # Example /// ``` /// use nested_containment_list::NestedContainmentList; /// use std::ops::Range; /// /// let nclist = NestedContainmentList::<Range<usize>, usize>::default(); /// ``` /// /// [`new()`]: Self::new() fn default() -> Self { Self::new() } } #[cfg(test)] mod tests { #[cfg(not(rust_1_36))] extern crate std as alloc; #[cfg(not(rust_1_36))] extern crate std as core; use alloc::vec; use core::{iter::FromIterator, ops::Range}; use NestedContainmentList; #[test] fn new() { let nclist = NestedContainmentList::<Range<usize>, usize>::new(); // Check that the sublist is empty. assert_none!(nclist.overlapping(&(..)).next()); } #[test] fn default() { let nclist = NestedContainmentList::<Range<usize>, usize>::default(); // Check that the sublist is empty. assert_none!(nclist.overlapping(&(..)).next()); } #[test] fn len() { let mut nclist = NestedContainmentList::new(); assert_eq!(nclist.len(), 0); nclist.insert(1..5); assert_eq!(nclist.len(), 1); } #[test] fn is_empty() { assert!(NestedContainmentList::<Range<usize>, usize>::new().is_empty()); } #[test] fn is_not_empty() { assert!(!NestedContainmentList::from_iter(vec![1..2]).is_empty()); } #[test] fn capacity() { let nclist = NestedContainmentList::<Range<usize>, usize>::with_capacity(10); assert_eq!(nclist.capacity(), 10); } #[test] fn insert_on_empty() { let mut nclist = NestedContainmentList::new(); nclist.insert(1..5); let mut sublist = nclist.overlapping(&(..)); assert_eq!(sublist.next().unwrap().value, &(1..5)); assert_none!(sublist.next()); } #[test] fn insert_contained() { let mut nclist = NestedContainmentList::new(); nclist.insert(1..5); nclist.insert(2..4); let mut sublist = nclist.overlapping(&(..)); let sublist_first_element = sublist.next().unwrap(); assert_eq!(sublist_first_element.value, &(1..5)); let mut sublist_first_element_sublist = sublist_first_element.sublist(); assert_eq!(sublist_first_element_sublist.next().unwrap().value, &(2..4)); assert_none!(sublist_first_element_sublist.next()); assert_none!(sublist.next()); } #[test] fn insert_containing() { let mut nclist = NestedContainmentList::new(); nclist.insert(2..4); nclist.insert(1..5); let mut sublist = nclist.overlapping(&(..)); let first_sublist_element = sublist.next().unwrap(); assert_eq!(first_sublist_element.value, &(1..5)); let mut first_sublist_element_sublist = first_sublist_element.sublist(); assert_eq!(first_sublist_element_sublist.next().unwrap().value, &(2..4)); assert_none!(first_sublist_element_sublist.next()); assert_none!(sublist.next()); } #[test] fn insert_contained_not_at_end() { let mut nclist = NestedContainmentList::new(); nclist.insert(1..5); nclist.insert(6..10); nclist.insert(2..4); let mut sublist = nclist.overlapping(&(..)); let first_sublist_element = sublist.next().unwrap(); assert_eq!(first_sublist_element.value, &(1..5)); let mut first_sublist_element_sublist = first_sublist_element.sublist(); assert_eq!(first_sublist_element_sublist.next().unwrap().value, &(2..4)); assert_none!(first_sublist_element_sublist.next()); assert_eq!(sublist.next().unwrap().value, &(6..10)); assert_none!(sublist.next()); } #[test] fn insert_contained_and_containing() { let mut nclist = NestedContainmentList::new(); nclist.insert(1..5); nclist.insert(3..4); nclist.insert(2..4); let mut sublist = nclist.overlapping(&(..)); let first_sublist_element = sublist.next().unwrap(); assert_eq!(first_sublist_element.value, &(1..5)); let mut first_sublist_element_sublist = first_sublist_element.sublist(); let second_sublist_element = first_sublist_element_sublist.next().unwrap(); assert_eq!(second_sublist_element.value, &(2..4)); let mut second_sublist_element_sublist = second_sublist_element.sublist(); assert_eq!( second_sublist_element_sublist.next().unwrap().value, &(3..4) ); assert_none!(first_sublist_element_sublist.next()); assert_none!(sublist.next()); } #[test] fn insert_equal() { let mut nclist = NestedContainmentList::new(); nclist.insert(1..5); nclist.insert(1..5); let mut sublist = nclist.overlapping(&(..)); let first_sublist_element = sublist.next().unwrap(); assert_eq!(first_sublist_element.value, &(1..5)); let mut first_sublist_element_sublist = first_sublist_element.sublist(); assert_eq!(first_sublist_element_sublist.next().unwrap().value, &(1..5)); assert_none!(first_sublist_element_sublist.next()); assert_none!(sublist.next()); } #[test] fn insert_disjoint() { let mut nclist = NestedContainmentList::new(); nclist.insert(1..5); nclist.insert(6..10); let mut sublist = nclist.overlapping(&(..)); assert_eq!(sublist.next().unwrap().value, &(1..5)); assert_eq!(sublist.next().unwrap().value, &(6..10)); assert_none!(sublist.next()); } #[test] fn insert_into_second_sublist() { let mut nclist = NestedContainmentList::from_iter(vec![1..4, 2..3, 5..9]); nclist.insert(6..8); let mut sublist = nclist.overlapping(&(..)); assert_eq!(sublist.next().unwrap().value, &(1..4)); let second_element = sublist.next().unwrap(); assert_eq!(second_element.value, &(5..9)); assert_eq!(second_element.sublist().next().unwrap().value, &(6..8)); assert_none!(sublist.next()); } #[test] fn remove_from_empty() { let mut nclist = NestedContainmentList::<Range<usize>, usize>::new(); assert!(!nclist.remove(&(1..5))); } #[test] fn remove() { let mut nclist = NestedContainmentList::from_iter(vec![1..5]); assert!(nclist.remove(&(1..5))); } #[test] fn remove_not_found() { let mut nclist = NestedContainmentList::from_iter(vec![1..5, 6..7]); assert!(!nclist.remove(&(1..4))); } #[test] fn remove_contained() { let mut nclist = NestedContainmentList::from_iter(vec![1..5, 2..4]); assert!(nclist.remove(&(2..4))); let mut sublist = nclist.overlapping(&(..)); let first_element = sublist.next().unwrap(); assert_eq!(first_element.value, &(1..5)); assert_none!(first_element.sublist().next()); assert_none!(sublist.next()); } #[test] fn remove_containing() { let mut nclist = NestedContainmentList::from_iter(vec![1..5, 0..6]); assert!(nclist.remove(&(0..6))); let mut sublist = nclist.overlapping(&(..)); let first_element = sublist.next().unwrap(); assert_eq!(first_element.value, &(1..5)); assert_none!(first_element.sublist().next()); assert_none!(sublist.next()); } #[test] fn remove_contained_and_containing() { let mut nclist = NestedContainmentList::from_iter(vec![1..5, 2..4, 3..4]); assert!(nclist.remove(&(2..4))); let mut sublist = nclist.overlapping(&(..)); let first_sublist_element = sublist.next().unwrap(); assert_eq!(first_sublist_element.value, &(1..5)); let mut first_sublist_element_sublist = first_sublist_element.sublist(); assert_eq!(first_sublist_element_sublist.next().unwrap().value, &(3..4)); assert_none!(first_sublist_element_sublist.next()); assert_none!(sublist.next()); } #[test] fn remove_from_second_sublist() { let mut nclist = NestedContainmentList::from_iter(vec![1..5, 2..4, 6..7]); assert!(nclist.remove(&(6..7))); } #[test] fn overlapping() { let nclist = NestedContainmentList::from_iter(vec![1..5, 3..4, 2..4, 6..7]); let query = 4..7; let mut overlapping = nclist.overlapping(&query); let first_element = overlapping.next().unwrap(); assert_eq!(first_element.value, &(1..5)); assert_none!(first_element.sublist().next()); let second_element = overlapping.next().unwrap(); assert_eq!(second_element.value, &(6..7)); assert_none!(second_element.sublist().next()); assert_none!(overlapping.next()); } #[test] fn overlapping_skip_first() { let nclist = NestedContainmentList::from_iter(vec![1..2, 3..4]); let query = 3..4; let mut overlapping = nclist.overlapping(&query); let first_element = overlapping.next().unwrap(); assert_eq!(first_element.value, &(3..4)); assert_none!(first_element.sublist().next()); assert_none!(overlapping.next()); } #[test] fn overlapping_contained() { let nclist = NestedContainmentList::from_iter(vec![1..5]); let query = 2..3; let mut overlapping = nclist.overlapping(&query); let first_element = overlapping.next().unwrap(); assert_eq!(first_element.value, &(1..5)); assert_none!(first_element.sublist().next()); assert_none!(overlapping.next()); } #[test] fn overlapping_starts_at_topmost_element() { let nclist = NestedContainmentList::from_iter(vec![1..4, 2..3]); let query = 2..4; let mut overlapping = nclist.overlapping(&query); let overlapping_element = overlapping.next().unwrap(); assert_eq!(overlapping_element.value, &(1..4)); let inner_overlapping_element = overlapping_element.sublist().next().unwrap(); assert_eq!(inner_overlapping_element.value, &(2..3)); } #[test] fn overlapping_stops_early() { let nclist = NestedContainmentList::from_iter(vec![1..4, 2..5]); let query = 1..2; let mut overlapping = nclist.overlapping(&query); assert_eq!(overlapping.next().unwrap().value, &(1..4)); assert_none!(overlapping.next()); } #[test] fn from_iter() { let nclist = NestedContainmentList::from_iter(vec![1..5, 3..4, 2..4, 6..7]); let mut sublist = nclist.overlapping(&(..)); let first_sublist_element = sublist.next().unwrap(); assert_eq!(first_sublist_element.value, &(1..5)); let mut first_sublist_element_sublist = first_sublist_element.sublist(); let second_sublist_element = first_sublist_element_sublist.next().unwrap(); assert_eq!(second_sublist_element.value, &(2..4)); let mut second_sublist_element_sublist = second_sublist_element.sublist(); assert_eq!( second_sublist_element_sublist.next().unwrap().value, &(3..4) ); assert_none!(first_sublist_element_sublist.next()); assert_eq!(sublist.next().unwrap().value, &(6..7)); assert_none!(sublist.next()); } #[test] fn into_iter() { let nclist = NestedContainmentList::from_iter(vec![1..5, 3..4, 2..4, 6..7]); let mut iter = nclist.into_iter(); let first_sublist_element = iter.next().unwrap(); assert_eq!(first_sublist_element.value, 1..5); let mut first_sublist_element_sublist = first_sublist_element.sublist(); let second_sublist_element = first_sublist_element_sublist.next().unwrap(); assert_eq!(second_sublist_element.value, 2..4); let mut second_sublist_element_sublist = second_sublist_element.sublist(); assert_eq!(second_sublist_element_sublist.next().unwrap().value, 3..4); assert_none!(first_sublist_element_sublist.next()); assert_eq!(iter.next().unwrap().value, 6..7); assert_none!(iter.next()); } }