A BK-tree implementation in Rust.
Here's some example usages:
```rust use bk_tree::{BKTree, metrics};
// A BK-tree using the Levenshtein distance metric. let mut tree: BKTree<&str> = BKTree::new(metrics::levenshtein);
tree.add("foo"); tree.add("bar"); tree.add("baz"); tree.add("bup");
tree.find("bar", 0); // returns vec!["bar"] tree.find("bar", 1); // returns vec!["bar", "baz"] tree.find("bup", 2); // returns vec!["bar", "baz", "bup"] ```