An Accidental Simula User Luca Cardelli Microsoft Research
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Proof-Carrying Authentication∗
Proof-Carrying Authentication∗ Andrew W. Appel and Edward W. Felten Secure Internet Programming Laboratory Department of Computer Science Princeton University Princeton, NJ 08544 USA August 9, 1999 Abstract Statements in these frameworks are represented as data structures that are often digitally signed We have designed and implemented a general to ensure their integrity. and powerful distributed authentication frame- work based on higher-order logic. Authenti- Several authentication frameworks exist; we cation frameworks — including Taos, SPKI, mention a few here as examples. The Taos SDSI, and X.509 — have been explained using operating system provided support for secure logic. We show that by starting with the logic, remote procedure call and data structures to we can implement these frameworks, all in the represent authority and identity [6]. X.509 [15] same concise and efficient system. Because our is a widely-used standard for expressing and us- logic has no decision procedure — although ing digital certificates. SPKI [4] and SDSI [14] proof checking is simple — users of the frame- (since merged under the joint name SPKI) work must submit proofs with their requests. were reactions to the perceived complexity of X.509; in both cases the ‘S’ stands for ‘simple.’ 1 Introduction PolicyMaker [3] is a language for expressing se- curity policies; it can be applied to distributed Distributed authentication frameworks allow security policies. Kerberos [12], unlike the other sharing of access to resources across adminis- frameworks, uses symmetric-key encryption to trative boundaries in a distributed system. The authenticate users. Each framework has a main abstractions they support are name-to- differerent semantics and offers a different kind key bindings, access control, and delegation. -
Object-Oriented Programming Basics with Java
Object-Oriented Programming Object-Oriented Programming Basics With Java In his keynote address to the 11th World Computer Congress in 1989, renowned computer scientist Donald Knuth said that one of the most important lessons he had learned from his years of experience is that software is hard to write! Computer scientists have struggled for decades to design new languages and techniques for writing software. Unfortunately, experience has shown that writing large systems is virtually impossible. Small programs seem to be no problem, but scaling to large systems with large programming teams can result in $100M projects that never work and are thrown out. The only solution seems to lie in writing small software units that communicate via well-defined interfaces and protocols like computer chips. The units must be small enough that one developer can understand them entirely and, perhaps most importantly, the units must be protected from interference by other units so that programmers can code the units in isolation. The object-oriented paradigm fits these guidelines as designers represent complete concepts or real world entities as objects with approved interfaces for use by other objects. Like the outer membrane of a biological cell, the interface hides the internal implementation of the object, thus, isolating the code from interference by other objects. For many tasks, object-oriented programming has proven to be a very successful paradigm. Interestingly, the first object-oriented language (called Simula, which had even more features than C++) was designed in the 1960's, but object-oriented programming has only come into fashion in the 1990's. -
Simula Mother Tongue for a Generation of Nordic Programmers
Simula! Mother Tongue! for a Generation of! Nordic Programmers! Yngve Sundblad HCI, CSC, KTH! ! KTH - CSC (School of Computer Science and Communication) Yngve Sundblad – Simula OctoberYngve 2010Sundblad! Inspired by Ole-Johan Dahl, 1931-2002, and Kristen Nygaard, 1926-2002" “From the cold waters of Norway comes Object-Oriented Programming” " (first line in Bertrand Meyer#s widely used text book Object Oriented Software Construction) ! ! KTH - CSC (School of Computer Science and Communication) Yngve Sundblad – Simula OctoberYngve 2010Sundblad! Simula concepts 1967" •# Class of similar Objects (in Simula declaration of CLASS with data and actions)! •# Objects created as Instances of a Class (in Simula NEW object of class)! •# Data attributes of a class (in Simula type declared as parameters or internal)! •# Method attributes are patterns of action (PROCEDURE)! •# Message passing, calls of methods (in Simula dot-notation)! •# Subclasses that inherit from superclasses! •# Polymorphism with several subclasses to a superclass! •# Co-routines (in Simula Detach – Resume)! •# Encapsulation of data supporting abstractions! ! KTH - CSC (School of Computer Science and Communication) Yngve Sundblad – Simula OctoberYngve 2010Sundblad! Simula example BEGIN! REF(taxi) t;" CLASS taxi(n); INTEGER n;! BEGIN ! INTEGER pax;" PROCEDURE book;" IF pax<n THEN pax:=pax+1;! pax:=n;" END of taxi;! t:-NEW taxi(5);" t.book; t.book;" print(t.pax)" END! Output: 7 ! ! KTH - CSC (School of Computer Science and Communication) Yngve Sundblad – Simula OctoberYngve 2010Sundblad! -
A Model of Inheritance for Declarative Visual Programming Languages
An Abstract Of The Dissertation Of Rebecca Djang for the degree of Doctor of Philosophy in Computer Science presented on December 17, 1998. Title: Similarity Inheritance: A Model of Inheritance for Declarative Visual Programming Languages. Abstract approved: Margaret M. Burnett Declarative visual programming languages (VPLs), including spreadsheets, make up a large portion of both research and commercial VPLs. Spreadsheets in particular enjoy a wide audience, including end users. Unfortunately, spreadsheets and most other declarative VPLs still suffer from some of the problems that have been solved in other languages, such as ad-hoc (cut-and-paste) reuse of code which has been remedied in object-oriented languages, for example, through the code-reuse mechanism of inheritance. We believe spreadsheets and other declarative VPLs can benefit from the addition of an inheritance-like mechanism for fine-grained code reuse. This dissertation first examines the opportunities for supporting reuse inherent in declarative VPLs, and then introduces similarity inheritance and describes a prototype of this model in the research spreadsheet language Forms/3. Similarity inheritance is very flexible, allowing multiple granularities of code sharing and even mutual inheritance; it includes explicit representations of inherited code and all sharing relationships, and it subsumes the current spreadsheet mechanisms for formula propagation, providing a gradual migration from simple formula reuse to more sophisticated uses of inheritance among objects. Since the inheritance model separates inheritance from types, we investigate what notion of types is appropriate to support reuse of functions on different types (operation polymorphism). Because it is important to us that immediate feedback, which is characteristic of many VPLs, be preserved, including feedback with respect to type errors, we introduce a model of types suitable for static type inference in the presence of operation polymorphism with similarity inheritance. -
Unifying Theories of Objects
Unifying Theories of Objects Michael Anthony Smith1;2 and Jeremy Gibbons1 1 Oxford University, UK. 2 Systems Assurance Group, QinetiQ, UK. [email protected] [email protected] Abstract. We present an approach to modelling Abadi{Cardelli-style object calculi as Unifying Theories of Programming (UTP) designs. Here we provide a core object calculus with an operational small-step evalua- tion rule semantics, and a corresponding UTP model with a denotational relational predicate semantics. For clarity, the UTP model is defined in terms of an operand stack, which is used to store the results of sub- programs. Models of a less operational nature are briefly discussed. The consistency of the UTP model is demonstrated by a structural induction proof over the operations of the core object calculus. Overall, our UTP model is intended to provide facilities for encoding both object-based and class-based languages. 1 Introduction Hoare and He's Unifying Theories of Programming (UTP) [6] can be used to formally define how results produced in one formal model can be translated as assumptions to another formal model. Essentially, programs are considered to be predicates that relate the values of their observable input and output variables (their alphabet). For example, the increment program x := x + 1 is typically defined by the relational predicate x 0 = x + 1, where predicate variables x and x 0 denote the input and output values of the program variable x. In general, the alphabet of a program P is denoted by αP; it is the disjoint union of P's input and output sets (inαP and outαP respectively), which in the case of the example is the set fx; x 0g. -
Programming Languages: Design and Implementation
طراحی و پیادهسازی زبان های برنامهسازی Programming Languages: Design and Implementation 40364 نیمسال دوم 1400 - 1399 slide 1 اهداف درس سیر طبیعی تحوﻻت مفاهیم و روش های طراحی و پیادهسازی نسل های مختلف زبان های برنامهسازی به روشی تجربی و گام به گام مهندسی زبان های برنامه سازی )زبان های ویژه دامنه( آشنایی با پیاده سازی مفسرها به ویژه بر بستر ماشین های مجازی اصول طراحی زبان های برنامه سازی و روش ها و ساختارهای داده ای به کار رفته در پیادهسازی یا محقق کردن محیط برنامه نویسی ایجاد توانایی ارزیابی، مقایسه و انتخاب میان زبان های برنامه سازی موجود برنامه سازی تابعی معناشناسی و استدﻻل پیرامون برنامه slide 2 Grading and Other Admin affairs Your grade components: • Final Exam • Mid Term Exam • Assignments (paper based) • Assignments (programming including a final project) • Class Presentation … Class Administration Policies: slide 3 Main References Daniel P. Friedman and Mitchell Wand, Essentials of Programming Languages, 3rd Edition, MIT Press, 2008. M.Felleisen, R.Findler, M.Flatt, S.Krishnamurthi, E.Barzilay, J.McCarthy, S.Tobin-Hochstadt, A Programmable Programming Language, Communications of the ACM, Vol. 61, No. 3, Pp. 62-71, March 2018. https://racket-lang.org/ My class and Slides slide 4 Other Useful General Text Books S.Krishnamurthi, Programming Languages: Application and Interpretation, 2nd Edition, http://cs.brown.edu/courses/cs173/2012/book/b ook.pdf, 2017. Peter Sestoft, Programming Language Concepts, 2nd Edition, 2017. Michael Scott, Programming Language Pragmatics, (with its complimentary CD) slide 5 Other Useful General Text Books -
Arxiv:2106.11534V1 [Cs.DL] 22 Jun 2021 2 Nanjing University of Science and Technology, Nanjing, China 3 University of Southampton, Southampton, U.K
Noname manuscript No. (will be inserted by the editor) Turing Award elites revisited: patterns of productivity, collaboration, authorship and impact Yinyu Jin1 · Sha Yuan1∗ · Zhou Shao2, 4 · Wendy Hall3 · Jie Tang4 Received: date / Accepted: date Abstract The Turing Award is recognized as the most influential and presti- gious award in the field of computer science(CS). With the rise of the science of science (SciSci), a large amount of bibliographic data has been analyzed in an attempt to understand the hidden mechanism of scientific evolution. These include the analysis of the Nobel Prize, including physics, chemistry, medicine, etc. In this article, we extract and analyze the data of 72 Turing Award lau- reates from the complete bibliographic data, fill the gap in the lack of Turing Award analysis, and discover the development characteristics of computer sci- ence as an independent discipline. First, we show most Turing Award laureates have long-term and high-quality educational backgrounds, and more than 61% of them have a degree in mathematics, which indicates that mathematics has played a significant role in the development of computer science. Secondly, the data shows that not all scholars have high productivity and high h-index; that is, the number of publications and h-index is not the leading indicator for evaluating the Turing Award. Third, the average age of awardees has increased from 40 to around 70 in recent years. This may be because new breakthroughs take longer, and some new technologies need time to prove their influence. Besides, we have also found that in the past ten years, international collabo- ration has experienced explosive growth, showing a new paradigm in the form of collaboration. -
Ole-Johan Dahl
Ole-Johan Dahl Born October 12, 1931, Mandal, Norway; with Kristen Nygaard, developer of the SIMULA programming language, which introduced classes and inheritance into the field of programming languages. Education: MS, numerical mathematics, University of Oslo, 1957. Professional Experience: Norwegian Defense Research Establishment (NDRE), 1952-1963; Norwegian Computing Center, 1963-1968; professor, computer science, University of Oslo, 1968-present. Dahl worked with the Norwegian Defense Research Establishment (NDRE) from 1952 to 1963 in computing and programming under Jan V. Gatwick. From 1956 onwards his main activity was software development. His master's thesis (“Numerical Mathematics,” 1957, University of Oslo) addressed the representation and manipulation of multidimensional arrays on a two-level store computer. His main contribution at the NDRE was a high-level programming language, MAC, used locally during the 1960s (first specification was dated 1957; the implemented version was modified as a result of the Algol effort). In 1963 he joined the Norwegian Computing Center for full-time work on SIMULA, and in 1968 he became a professor of computer science, then a new discipline at the University of Oslo. His main research during recent years has been in the areas of program architecture, specification tools, and verification techniques. From 1964 to 1976 he was the Norwegian delegate to IFIP Technical Committee 2 (Programming Languages), and from 1970 to 1977 he was a working member of IFIP Working Group 2.2 (Language Definition). He has been a member of IFIP Working Group 2.3 (Programming Methodology) since its founding in Oslo in 1969.1 BIBLIOGRAPHY Biographical Nygaard, Kristen, and Ole-Johan Dahl, “The Development of the SIMULA Languages,” in Wexelblat, Richard L., ed., History of Programming Languages, Academic Press, New York, 1981. -
Ole-Johan Dahl- A.M
12/19/2016 Ole-Johan Dahl- A.M. Turing Award Winner A .M . TURING CENTENARY GELEBRATION WEBCAST Search TYPE HERE MORE ACM AWARDS A.M. TURING AWARD WINNERS BY... ALPHABETICAL LISTING YEAR OF THE AWARD RESEARCH SUBJECT OLE-JOHAN DAHL Norway- 2001 CITATJON With Kristen Nygaard, for ideas fundamental to the emergence of object oriented programming, through their design of the programming languages Simula I and Simula 67. SHORT ANNOTATED ACM DL RESEARCH ADDITIONAL PHOTOGRAPHS BJBLJOGRAPHY AUTHOR PROFILE SUBJECTS MATERIALS BIRTH: Object-oriented programming is a dominant programming paradigm of this age. Fundamental to the 12th October 1931in Mandal, Norway emergence of this paradigm were core concepts such as objects, classes, and inheritance with virtual quantities, all clear1y established in Oie Johan Dahl and Kristen Nygaard's discrete event simulation language Simula I and DEATH: general programming language Simula 67. The objects integrale data, procedural, and cooperating action 29th June 2002 from Lymphatic Cancer sequence aspects into one very general and powerful unifying entity. at Asker, Norway By embodying these core concepts in a language designed both for system description and programming, Dahl EDUCATION: and Nygaard provided both a logical and a notalienal basis for the ideas. Software could be built in layers of MS in Numerical Mathematics, abstraction, each one relying on the description and conceptual plattarm implemented by the previous layers. By University of Oslo (1957). defining Simula 67 to be an extension of an international standard language, Algol-60, this medium of expression was accessible and available to the entire research community. Simula shaped and sped the EXPERIENCE: emergence of object-<lriented programming and the management discipline that accompanies it by many years. -
Object-Oriented Programming in the Beta Programming Language
OBJECT-ORIENTED PROGRAMMING IN THE BETA PROGRAMMING LANGUAGE OLE LEHRMANN MADSEN Aarhus University BIRGER MØLLER-PEDERSEN Ericsson Research, Applied Research Center, Oslo KRISTEN NYGAARD University of Oslo Copyright c 1993 by Ole Lehrmann Madsen, Birger Møller-Pedersen, and Kristen Nygaard. All rights reserved. No part of this book may be copied or distributed without the prior written permission of the authors Preface This is a book on object-oriented programming and the BETA programming language. Object-oriented programming originated with the Simula languages developed at the Norwegian Computing Center, Oslo, in the 1960s. The first Simula language, Simula I, was intended for writing simulation programs. Si- mula I was later used as a basis for defining a general purpose programming language, Simula 67. In addition to being a programming language, Simula1 was also designed as a language for describing and communicating about sys- tems in general. Simula has been used by a relatively small community for many years, although it has had a major impact on research in computer sci- ence. The real breakthrough for object-oriented programming came with the development of Smalltalk. Since then, a large number of programming lan- guages based on Simula concepts have appeared. C++ is the language that has had the greatest influence on the use of object-oriented programming in industry. Object-oriented programming has also been the subject of intensive research, resulting in a large number of important contributions. The authors of this book, together with Bent Bruun Kristensen, have been involved in the BETA project since 1975, the aim of which is to develop con- cepts, constructs and tools for programming. -
Admission Control for Independently-Authored Realtime Applications
Admission Control for Independently-authored Realtime Applications by Robert Kroeger Athesis presented to the University of Waterloo in fulfilment of the thesis requirement for the degree of Doctor of Philosophy in Computer Science Waterloo, Ontario, Canada, 2004 c Robert Kroeger 2004 AUTHOR’S DECLARATION FOR ELECTRONIC SUBMISSION OF A THESIS I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii Abstract This thesis presents the LiquiMedia operating system architecture. LiquiMedia is specialized to schedule multimedia applications. Because they generate output for a human observer, multimedia applications such as video games, video conferencing and video players have both unique scheduling requirements and unique allowances: a multimedia stream must synchro- nize sub-streams generated for different sensory modalities within 20 milliseconds, it is not successfully segregated until it has existed for over 200 milliseconds and tolerates occasional scheduling failures. LiquiMedia is specialized around these requirements and allowances. First, LiquiMedia synchronizes multimedia tasks by invoking them from a shared realtime timer interrupt. Sec- ond, owing to multimedia’s tolerance of scheduling failures, LiquiMedia schedules tasks based on a probabilistic model of their running times. Third, LiquiMedia can infer per-task models while a user is segregating the streams that the tasks generate. These specializations provide novel capabilities: up to 2.5 times higher utilization than RMS scheduling, use of an atomic task primitive 9.5 times more efficient than preemptive threading, and most importantly, the ability to schedule arbitrary tasks to a known probability of realtime execution without a priori knowledge of their running times. -
Types for Safe Locking: Static Race Detection for Java
Types for Safe Locking: Static Race Detection for Java MARTIN ABADI Microsoft Research and University of California at Santa Cruz CORMAC FLANAGAN University of California at Santa Cruz and STEPHEN N. FREUND Williams College This article presents a static race-detection analysis for multithreaded shared-memory programs, focusing on the Java programming language. The analysis is based on a type system that captures many common synchronization patterns. It supports classes with internal synchronization, classes that require client-side synchronization, and thread-local classes. In order to demonstrate the effectiveness of the type system, we have implemented it in a checker and applied it to over 40,000 lines of hand-annotated Java code. We found a number of race conditions in the standard Java libraries and other test programs. The checker required fewer than 20 additional type annotations per 1,000 lines of code. This article also describes two improvements that facilitate checking much larger programs: an algorithm for annotation inference and a user interface that clarifies warnings generated by the checker. These extensions have enabled us to use the checker for identifying race conditions in large-scale software systems with up to 500,000 lines of code. Categories and Subject Descriptors: F.3.1 [Logics and Meanings of Programs]: Specifying and Verifying and Reasoning about Programs; D.2.4 [Software Engineering]: Software/Program Ver- ification—Reliability; D.3.2 [Programming Languages]: Language Classifications—Concurrent, distributed, and parallel languages; D.3.1 [Programming Languages]: Formal Definitions and Theory—Semantics, syntax Martin Abadi’s work was started at Compaq; it was also partly supported by the National Science Foundation under Grants CCR-0204162 and CCR-0341179, and by faculty research funds granted by the University of California, Santa Cruz.