**Packages**- is:exact

The sort function implements a stable sorting algorithm. It is
a special case of sortBy, which allows the programmer to supply
their own comparison function.
Elements are arranged from lowest to highest, keeping duplicates in
the order they appeared in the input.

>>> sort [1,6,4,3,2,5] [1,2,3,4,5,6]

Extract the elements after the head of a list, which
must be non-empty.

>>> tail [1, 2, 3] [2,3] >>> tail [1] [] >>> tail [] Exception: Prelude.tail: empty list

Return all the elements of a list except the last one.
The list must be non-empty.

>>> init [1, 2, 3] [1,2] >>> init [1] [] >>> init [] Exception: Prelude.init: empty list

reverse `xs` returns the elements of `xs` in
reverse order. `xs` must be finite.

>>> reverse [] [] >>> reverse [42] [42] >>> reverse [2,5,7] [7,5,2] >>> reverse [1..] * Hangs forever *

cycle ties a finite list into a circular one, or equivalently,
the infinite repetition of the original list. It is the identity on
infinite lists.

>>> cycle [] Exception: Prelude.cycle: empty list >>> cycle [42] [42,42,42,42,42,42,42,42,42,42... >>> cycle [2, 5, 7] [2,5,7,2,5,7,2,5,7,2,5,7...