Crate idlset

IDLSet - Fast u64 integer set operations

IDLSet is a specialised library for fast logical set operations on u64. For example, this means union (or), intersection (and) and not operations on sets. In the best case, speed ups of 15x have been observed with the general case performing approximately 4x faster that a Vec based implementation.

These operations are heavily used in low-level implementations of databases for their indexing logic, but has applications with statistical analysis and other domains that require logical set operations.

This seems very specific to only use u64, but has been chosen for a good reason. On 64bit cpus, native 64bit operations are faster than 32/16. Additionally, due to the design of the library, unsigned types are simpler to operate on for the set operations.

Structs

IDLBitRange	An ID List of u64 values, that uses a compressed representation of u64 to speed up set operations, improve cpu cache behaviour and consume less memory.
IDLBitRangeIter	An iterator over the set of values that exists in an IDLBitRange. This can be used to extract the decompressed values into another form of datastructure, perform map functions or simply iteration with a for loop.

Traits

AndNot

Bit trait representing the equivalent of a & (!b). This allows set operations such as "The set A does not contain any element of set B".