# Unbounded Interval Tree

A Rust implementation of an interval tree, based on the one described by Cormen et al. (2009, Section 14.3: Interval trees, pp. 348–354). An interval tree is useful to query efficiently a database of intervals. This implementation is generic in that it works with intervals of values implementing `Ord+Clone`

traits. The bounds can be inclusive, exclusive, or unbounded. Here are some examples of valid intervals:

- [5, 9] <- inclusive/inclusive integers
- [-2.3, 18.81) <- inclusive/exclusive floats
- ("abc", "hi"] <- exclusive/inclusive strings
- (-inf, November 7 2019] <- unbounded/inclusive dates

## How To Use

I would suggest to look at the examples part of the documentation (as they are tested by the Rust ecosystem), but here's a current example.

```
use unbounded_interval_tree::IntervalTree;
use std::ops::Bound::{Included, Excluded, Unbounded};
// Default interval tree.
let mut tree = IntervalTree::default();
// Ranges are defined as a 2-ple of Bounds.
let interval1 = (Included(5), Excluded(9));
let interval2 = (Unbounded, Included(-2));
let interval3 = (Included(30), Included(30));
// Add intervals to the tree.
tree.insert(interval1);
tree.insert(interval2);
tree.insert(interval3);
// Iterate through the intervals inorder.
for (start, end) in tree.iter() {
println!("Start: {:?}\tEnd: {:?}", start, end);
}
// Get overlapping intervals.
let overlaps = tree.get_interval_overlaps(
&(Included(0), Excluded(30)));
// Get the difference between the database
// of intervals and the query interval.
let diff = tree.get_interval_difference(
(Included(0), Excluded(30)));
```

## Roadmap

*What's next...*

- Add another
`IntervalTree`

constructor (other than the default one). - Allow to remove intervals from the tree (started in the
`delete`

branch). - Keep the tree balanced, by rotating during insertions/deletions
- Assert that the start bound of an interval is smaller or equal to the end bound of the same interval.