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#Tuple Spaces and All That#

What is a tuple space?

A tuple is a finite list of elements that can be used to represent a data item or a message. Tuples can represent, for example, GPS coordinates

<50° 18'00”N, 120° 30'0”W>
dates <1984, "September", 13>
user credentials <"Alice", 1234>
groceries missing in the fridge <"milk">
and so on. A *tuple space* is a collection of tuples. In general, the term collection has to be understood in the more general sense. However, the traditional interpretation is to consider the simple case of unordered collections of tuples, i.e. multisets of tuples. This is precisely what we shall consider in this chapter. Recall that a multiset di↵ers from a set in that an element can appear more than once. Here is an example of a tuple space representing a grocery list

It is worth to remark that a multiset di↵ers from a list in that the order of elements does not matter.

Exempt from "Lafuente, A. L., (January 2, 2017) Teaching material for 02148 “Introduction to Coordination in Distributed Applications”, Technical University of Denmark"