Crate group-by is a library for efficiently iterating on a slice by groups defined by a function that specify if two elements are in the same group.

Example: Linear Searched Immutable Groups

You can use a function return true if two elements are in the same group.

The LinearGroupBy iterator will always gives contiguous elements to the predicate function.

use slice_group_by::GroupBy;

let slice = &[1, 1, 1, 3, 3, 2, 2, 2];

let mut iter = slice.linear_group_by(|a, b| a == b);

assert_eq!(iter.next(), Some(&[1, 1, 1][..]));
assert_eq!(iter.next(), Some(&[3, 3][..]));
assert_eq!(iter.next(), Some(&[2, 2, 2][..]));
assert_eq!(iter.next(), None);

Example: Binary Searched Mutable Groups

It is also possible to get mutable non overlapping groups of a slice.

The BinaryGroupBy/Mut and ExponentialGroupBy/Mut iterators will not necessarily gives contiguous elements to the predicate function. The predicate function should implement an order consistent with the sort order of the slice.

use slice_group_by::GroupByMut;

let slice = &mut [1, 1, 1, 2, 2, 2, 3, 3];

let mut iter = slice.binary_group_by_mut(|a, b| a == b);

assert_eq!(iter.next(), Some(&mut [1, 1, 1][..]));
assert_eq!(iter.next(), Some(&mut [2, 2, 2][..]));
assert_eq!(iter.next(), Some(&mut [3, 3][..]));
assert_eq!(iter.next(), None);