data:type:collection:sequence

Table of Contents

About

A sequence is an abstract collection:

of non-unique element
where order matters - ie (A,B) is not equal to (B,A)

non-unique means that it allows duplicate member (the same element/value may occur more than once).

Order matter for equivalence	Duplicate is allowed	Collection Type
false	false	set
false	true	Bag
true	false	OrderedSet
true	true	Sequence

Example

(M, A, R, Y) is a sequence of letters with the letter M first and Y last.
(M, A, R, Y) differs from (A, R, M, Y)

Properties

Rank / Index

The position of an element in a sequence is its rank or index.

Cardinality

Collection - Cardinality (Size/Length) - In computer science

Finite

A finite sequence is called a list

Infinite

A infinite sequence is called a stream and is generally read through a iterator pattern.

Access type

It's a data structures with no or slow random access.

Documentation / Reference

wiki/Sequence