thinset 0.2.0

A data structure for sparse sets of unsigned integers that sacrifices space for speed.
Documentation

crates.io Documentation Rust CI rustc 1.0+ Dependency Status Download Status

Usage

Add this to your Cargo.toml:

[dependencies]
thinset = "0.1"

Description

An implementation of a set using a pair of sparse and dense arrays as backing stores.

This type of set is useful when you need to efficiently track set membership for integers from a large universe, but the values are relatively spread apart.

The sparse set supports constant-time insertion, removal, lookups as expected. In addition:

  • Compared to the standard library's HashSet, clearing the set is constant-time instead of linear time.
  • Compared to bitmap-based sets like the bit-set crate, iteration over the set is proportional to the cardinality of the set (how many elements you have) instead of proportional to the maximum size of the set.

The main downside is that the set requires more memory than other set implementations.

The implementation is based on the paper "An efficient representation for sparse sets" (1993) by Briggs and Torczon.

Examples

use thinset::SparseSet;

// Specify a maximum value for the set
let mut s: SparseSet<usize> = SparseSet::new(100);
s.insert(0);
s.insert(3);
s.insert(7);

s.remove(7);

if !s.contains(7) {
    println!("There is no 7");
}

// Print 0, 1, 3 in some order
for x in s.iter() {
    println!("{}", x);
}

License

Dual-licensed for compatibility with the Rust project.

Licensed under the Apache License Version 2.0: http://www.apache.org/licenses/LICENSE-2.0, or the MIT license: http://opensource.org/licenses/MIT, at your option.