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(computer science)
A horizontal row of data items in a relational data structure; corresponds to a record or segment in other types of data structures.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.




In functional languages, a data object containing two or more components. Also known as a product type or pair, triple, quad, etc. Tuples of different sizes have different types, in contrast to lists where the type is independent of the length. The components of a tuple may be of different types whereas all elements of a list have the same type. Examples of tuples in Haskell notation are (1,2), ("Tuple",True), (w,(x,y),z). The degenerate tuple with zero components, written (), is known as the unit type since it has only one possible value which is also written ().

The implementation of tuples in a language may be either "lifted" or not. If tuples are lifted then (bottom,bottom) /= bottom and the evaluation of a tuple may fail to terminate. E.g. in Haskell:

f (x,y) = 1 --> f bottom = bottom f (bottom,bottom) = 1

With lifted tuples, a tuple pattern is refutable. Thus in Haskell, pattern matching on tuples is the same as pattern matching on types with multiple constructors (algebraic data types) - the expression being matched is evaluated as far as the top level constructor, even though, in the case of tuples, there is only one possible constructor for a given type.

If tuples are unlifted then (bottom, bottom) = bottom and evaluation of a tuple will never fail to terminate though any of the components may. E.g. in Miranda:

f (x,y) = 1 --> f bottom = 1 f (bottom,bottom) = 1

Thus in Miranda, any object whose type is compatible with a tuple pattern is assumed to match at the top level without evaluation - it is an irrefutable pattern. This also applies to user defined data types with only one constructor. In Haskell, patterns can be made irrefutable by adding a "~" as in

f ~(x,y) = 1.

If tuple constructor functions were strict in all their arguments then (bottom,x) = (x,bottom) = bottom for any x so matching a refutable pattern would fail to terminate if any component was bottom.
This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)


(1) In a relational database, a tuple is one record (one row). See record and relational database.

(2) A set of values passed from one programming language to another application program or to a system program such as the operating system. Typically separated by commas, the values may be parameters for a function call or a set of data values for a database. See function.
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References in periodicals archive ?
Finally, C adds the tuple < [ID.sub.i], [W.sub.i], Q[W.sub.i], [x.sub.i] > in the list [H.sub.2.sup.LIST] and respond to the adversary A with [H.sub.2]([ID.sub.i], [W.sub.i]) = Q[W.sub.i]
In this way, the Replier agent can store a tuple in the local tuple space of the cluster leader node, which represents the credit value assigned to it.
is called the smoothed signal tuple and used to construct a learning set [mathematical expression not reproducible] by putting
When A 1 executes the query with the tuple ([m.sub.i], [ID.sub.i], [pk.sub.i], [R.sub.i]) C checks if a tuple [mathematical expression not reproducible]; if it exists, it returns [[beta].sub.i] to [A.sub.1]; otherwise, C randomly selects [[beta].sub.i].
The two different methods to execute these extensions are tuple time stamping and attribute time stamping.
Problem statement: Find a differentiable bijective mapping function m that takes as input the tuples of the input image and outputs a new set of tuples whose statistics match the statistics of the target tuples.
The tuples in the database are grouped and watermarks are embedded into groups.
Every tuple in the original table should be assigned to one group in anonymity table.
The tuple level uncertainty describes the presence or absence of a tuple, and the feature level uncertainty does not involve the uncertainty of entire tuples.
In both cases, [S.sub.1] inserts a tuple ([ID.sub.i], [[alpha].sub.i], [c.sub.i], [Q.sub.i]) in a list [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] to keep the track of the queries.