SRFI 153: Ordered Sets

by John Cowan

status: final (2023-05-01)

keywords: Data Structure

See also SRFI 128: Comparators (reduced) and SRFI 146: Mappings.


Osets are immutable collections that can contain any Scheme objects as long as a total order exists among the objects. Osets enforce the constraint that no two elements can be the same in the sense of the oset's associated equality predicate. The elements in an oset appear in a fixed order determined by the comparator used to create it.