On theories of names and references in formal languages and implications for functional and object-oriented programming

Functional Language ◽

Limited Extent ◽

Contextual Equivalence ◽

Standing Problem

The long-standing problem of adequate formalization of local names in mathematical formulae and semantics of references in object-oriented languages taken “as is” without objects, is discussed. Reasons why the existing approaches cannot be considered suitable solutions, are explained. An introduction to the relatively recent works on the theories of names and references of the group headed by Andrew Pitts, is given. The notion of referential transparency, in which contextual equivalence is used instead of the usual equality of values, is analyzed. This is the main property, which these theories are based upon: it is preserved when a purely functional language is extended with names and references as data. It is argued that such referential transparency, along with many others, can be preserved for mutable objects that change to a limited extent. This leads to a model of computation between functional and object-oriented ones, allowing for a deterministic parallel implementation.

Static Typing for Object-Oriented Programming

DAIMI Report Series ◽

10.7146/dpb.v20i355.6585 ◽

1991 ◽

Vol 20 (355) ◽

Cited By ~ 4

Author(s):

Jens Palsberg ◽

Michael I. Schwartzbach

Keyword(s):

Partial Order ◽

Object Oriented ◽

Finite Sets ◽

Static Typing

We develop a theory of statically typed object-oriented languages. It represents classes as labeled, regular trees, types as finite sets of classes, and subclassing as a partial order on trees. We show that our subclassing order strictly generalizes inheritance, and that a novel genericity mechanism arises as an order-theoretic complement. This mechanism, called class substitution, is pragmatically useful and can be implemented efficiently.

Substitution Polymorphism for Object-Oriented Programming

DAIMI Report Series ◽

10.7146/dpb.v19i305.6698 ◽

1990 ◽

Vol 19 (305) ◽

Author(s):

Jens Palsberg ◽

Michael I. Schwartzbach

Keyword(s):

Type System ◽

Object Oriented ◽

The Novel ◽

Type Checking ◽

Generic Class ◽

We introduce substitution polymorphism as a new basis for typed object-oriented languages. While avoiding subtypes and polymorphic types, this mechanism enables optimal static type-checking of generic classes and polymorphic functions. The novel idea is to view a class as having a family of implicit subclasses, each of which is obtained through a substitution of types. This allows instantiation of a generic class to be merely subclassing and resolves the problems in the Eiffel type system reported by Cook. All subclasses, including the implicit ones, can reuse the code implementing their superclass.

A Unified Type System for Object-Oriented Programming

DAIMI Report Series ◽

10.7146/dpb.v19i341.6571 ◽

1990 ◽

Vol 19 (341) ◽

Author(s):

Jens Palsberg ◽

Michael I. Schwartzbach

Keyword(s):

Type System ◽

Object Oriented ◽

Type Systems ◽

Type Checking ◽

Separate Compilation ◽

Set Inclusion ◽

New Type ◽

Efficient Type ◽

We present a new type system for object-oriented languages with assignments. Types are sets of classes, subtyping is set inclusion, and genericity is class substitution. The type system enables separate compilation, and unifies, generalizes, and simplifies the type systems underlying SIMULA/BETA, C++, EIFFEL, and Typed Smalltalk, and the type system with type substitutions proposed by Palsberg and Schwartzbach, Classes and types are both modeled as node-labeled, ordered regular trees; this allows an efficient type-checking algorithm.

Compilation and equivalence of imperative objects

Journal of Functional Programming ◽

10.1017/s0956796899003482 ◽

1999 ◽

Vol 9 (4) ◽

pp. 373-426 ◽

Cited By ~ 4

Author(s):

ANDREW D. GORDON ◽

PAUL D. HANKIN ◽

SØREN B. LASSEN

Keyword(s):

Operational Semantics ◽

Direct Proof ◽

Object Oriented ◽

Small Step ◽

Abstract Machine ◽

Program Equivalence ◽

Contextual Equivalence ◽

We adopt the untyped imperative object calculus of Abadi and Cardelli as a minimal setting in which to study problems of compilation and program equivalence that arise when compiling object-oriented languages. We present both a big-step and a small-step substitution-based operational semantics for the calculus. Our first two results are theorems asserting the equivalence of our substitution-based semantics with a closure-based semantics like that given by Abadi and Cardelli. Our third result is a direct proof of the correctness of compilation to a stack-based abstract machine via a small-step decompilation algorithm. Our fourth result is that contextual equivalence of objects coincides with a form of Mason and Talcott's CIU equivalence; the latter provides a tractable means of establishing operational equivalences. Finally, we prove correct an algorithm, used in our prototype compiler, for statically resolving method offsets. This is the first study of correctness of an object-oriented abstract machine, and of operational equivalence for the imperative object calculus.

Virtual Classes - a powerful mechanism in object-oriented programming

DAIMI Report Series ◽

10.7146/dpb.v18i283.6660 ◽

1989 ◽

Vol 18 (283) ◽

Author(s):

Ole Lehrmann Madsen ◽

Birger Møller-Pedersen

Keyword(s):

Object Oriented ◽

Powerful Technique ◽

General Properties ◽

Key Concepts ◽

Virtual Class ◽

Virtual Classes ◽

Powerful Mechanism ◽

Typed Languages

The notations of class, subclass and virtual procedure are fairly well understood and recognized as some of the key concepts in object-oriented programming. The possibility of modifying a virtual procedure in a subclass is a powerful technique for specializing the general properties of the superclass.In most object-oriented languages, the attributes of an object may be references to objects and (virtual) procedures. In Simula and BETA it is also possible to have class attributes. The power of class attributes has not yet been widely recognized. In BETA a class may also have virtual class attributes. This makes it possible to defer part of the specification of a class attribute to a subclass. In this sense virtual classes are analogous to virtual procedures. Virtual classes are mainly interesting within strongly typed languages where they provide a mechanism for defining general parameterized classes such as set, vector and list. In this sense they provide an alternative to generics. Although the notion of virtual class originates from BETA, it is presented as a general language mechanism.

Volume 2: Applied Fluid Mechanics; Electromechanical Systems and Mechatronics; Advanced Energy Systems; Thermal Engineering; Human Factors and Cognitive Engineering ◽

Computer-Aided Design of Mechatronic Systems Using Multiobjective Optimization and Object-Oriented Languages

10.1115/esda2012-82212 ◽

2012 ◽

Cited By ~ 3

Author(s):

Didier Casner ◽

Jean Renaud ◽

Dominique Knittel

Keyword(s):

Computer Aided Design ◽

Multidisciplinary Design Optimization ◽

Object Oriented ◽

Multidisciplinary Design ◽

Modeling Language ◽

Mechatronic Systems ◽

Aided Design ◽

Oriented Programming Language

This paper deals with the fast modeling and fast multiobjective optimal design of mechatronic systems. To solve this problem, the object-oriented modeling language Modelica and object-oriented programming language Java have been used to build an innovate software platform. This platform has been designed to allow multidisciplinary design optimization of complex systems using a free platform. This platform only contains open-source tools and frameworks and was validated on an optimization application: the stabilization of a quarter-car system.

Mutation Testing Applied to Object-Oriented Languages

Encyclopedia of Information Science and Technology, Fourth Edition ◽

10.4018/978-1-5225-2255-3.ch649 ◽

2018 ◽

pp. 7459-7469

Author(s):

Pedro Delgado-Pérez ◽

Inmaculada Medina-Bulo ◽

Juan José Domínguez-Jiménez

Keyword(s):

Programming Languages ◽

Object Oriented ◽

Mutation Testing ◽

Mutation Operators ◽

Current State ◽

Suitable Technique ◽

Test Suites ◽

Mutation testing is a suitable technique to determine the quality of test suites designed for a certain program. The set of mutation operators and the overall technique should be developed around each programming language in particular. The structures related to the object-oriented paradigm require a tailored analysis addressing them. However, class mutation operators for these languages have not been analyzed at the same extent as traditional operators for procedural languages in the literature. The purpose of the chapter is to look in depth at the development and the current state of mutation testing, and more specifically, with regard to object-oriented programming languages.

Advances in Computer and Electrical Engineering - Advanced Methodologies and Technologies in Network Architecture, Mobile Computing, and Data Analytics ◽

Mutation Testing Applied to Object-Oriented Languages

10.4018/978-1-5225-7598-6.ch105 ◽

2019 ◽

pp. 1426-1438

Author(s):

Pedro Delgado-Pérez ◽

Inmaculada Medina-Bulo ◽

Juan José Domínguez-Jiménez

Keyword(s):

Programming Languages ◽

Object Oriented ◽

Mutation Testing ◽

Mutation Operators ◽

Current State ◽

Suitable Technique ◽

Test Suites ◽

Compilation and Equivalence of Imperative Objects

BRICS Report Series ◽

10.7146/brics.v4i19.21677 ◽

1997 ◽

Vol 4 (19) ◽

Cited By ~ 2

Author(s):

Andrew D. Gordon ◽

Paul D. Hankin ◽

Søren B. Lassen

Keyword(s):

Operational Semantics ◽

Direct Proof ◽

Object Oriented ◽

Small Step ◽

Abstract Machine ◽

Program Equivalence ◽

Contextual Equivalence ◽

We adopt the untyped imperative object calculus of Abadi and Cardelli as a minimal setting in which to study problems of compilation and program equivalence that arise when compiling object-oriented languages. We present both a big-step and a small-step substitution-based operational semantics for the calculus and prove them equivalent to the closure-based operational semantics given by Abadi and Cardelli. Our first result is a direct proof of the correctness of compilation to a stack-based abstract machine via a small-step decompilation algorithm. Our second result is that contextual equivalence of objects coincides with a form of Mason and Talcott's CIU equivalence; the latter provides a tractable means of establishing operational equivalences. Finally, we prove correct an algorithm, used in our prototype compiler, for statically resolving method offsets. This is the first study of correctness of an object-oriented abstract machine, and of operational equivalence for the imperative object calculus. This report is superseded by BRICS-RS-98-55.

Partial Evaluation for Class-Based Object-Oriented Languages

DAIMI Report Series ◽

10.7146/dpb.v29i552.7109 ◽

2000 ◽

Vol 29 (552) ◽

Cited By ~ 1

Author(s):

Ulrik Pagh Schultz

Keyword(s):

Partial Evaluation ◽

Object Oriented ◽

Formalized Description ◽

Object-oriented programming facilitates the development of generic software, but at a cost in terms of performance of the final program. We use partial evaluation to automatically map generic object-oriented software into specific implementations. In this paper we give a concise and formalized description of how partial evaluation specializes an object-oriented program.