The Joy of Sets

Connor, Richard; Atkinson, Malcolm; Berman, Sonia; Cutts, Quintin; Kirby, Graham N. C.; Morrison, Ronald

doi:10.1007/978-1-4471-3564-7_23

Cited by 5 publications

(2 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Others ( [3], [9], [20]) have considered the role of user-defined equalities in query operators. In [3] and [9], sets are considered tied to a single notion of equality (equivalent in spirit to our distinguisher equality). Constructor equalities are not differentiated.…”

Section: A Return To Our Motivating Examplementioning

confidence: 99%

“…Thus integer equality (which might be implemented as a bitwise comparison of bit strings) must necessarily have a different implementation than set equality (which will likely be implemented using looping). For this reason, it is generally accepted ( [3], [9], [11], [12], [16], [4]) that users should be able to provide their own user-defined equality predicates specific to user-defined types.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

To Form a More Perfect Union (Intersection, Difference)

Cherniack

Zdonik

Nodine

1995

Electronic Workshops in Computing

View full text Add to dashboard Cite

The AQUA [16] query algebra allows user-defined equivalence relations as arguments to query operators that generalize standard set operations. These predicates determine what objects are included in the query result, and the duplicates that must be removed.While an expressive enhancement, the use of arbitrary equivalence relations to decide set membership can result in sets with counterintuitive behavior, and therefore can make queries return unreasonable results. In this paper, we show that equality predicates assume two roles with respect to sets. Distinguishers differentiate between set members and implicitly give meaning to standard set properties such as set equality. Constructors determine which object from input sets contribute to the query result. The requirements of distinguishers and constructors differ. AQUA's set operators are problematic because they use constructors where distinguishers are required. We propose alternatives to AQUA's set operators that address this limitation.

show abstract

Section: A Return To Our Motivating Examplementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

To Form a More Perfect Union (Intersection, Difference)

Cherniack

Zdonik

Nodine

1995

Electronic Workshops in Computing

View full text Add to dashboard Cite

show abstract

Current Directions in Hyper-Programming

Morrison

Connor

Cutts

et al. 2000

Lecture Notes in Computer Science

View full text Add to dashboard Cite

The traditional representation of a program is as a linear sequence of text. At some stage in the execution sequence the source text is checked for type correctness and its translated form is linked to values in the environment. When this is performed early in the execution process, confidence in the correctness of the program is raised. During program execution, tools such as debuggers are used to inspect the running state of programs. Relating this state to the linear text is often problematical. We have developed a technique, hyperprogramming, that allows the representations of source programs to include direct links (hyper-links) to values, including code, that already exist in the environment. Hyper-programming achieves our two objectives of being able to link earlier than before, at program composition time, and to represent sharing and thus closure and through this the run-time state of a program. This paper reviews our work on hyper-programming and proposes some current research areas.

show abstract