singleton package:containers

A map of one element.
singleton 1 'a'        == fromList [(1, 'a')]
size (singleton 1 'a') == 1
A set of one element.
A map with a single element.
singleton 1 'a'        == fromList [(1, 'a')]
size (singleton 1 'a') == 1
A singleton sequence.
Create a singleton set.