Squeakjs: a Modern and Practical Smalltalk That Runs in Any Browser
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The Future: the Story of Squeak, a Practical Smalltalk Written in Itself
Back to the future: the story of Squeak, a practical Smalltalk written in itself Dan Ingalls, Ted Kaehler, John Maloney, Scott Wallace, and Alan Kay [Also published in OOPSLA ’97: Proc. of the 12th ACM SIGPLAN Conference on Object-oriented Programming, 1997, pp. 318-326.] VPRI Technical Report TR-1997-001 Viewpoints Research Institute, 1209 Grand Central Avenue, Glendale, CA 91201 t: (818) 332-3001 f: (818) 244-9761 Back to the Future The Story of Squeak, A Practical Smalltalk Written in Itself by Dan Ingalls Ted Kaehler John Maloney Scott Wallace Alan Kay at Apple Computer while doing this work, now at Walt Disney Imagineering 1401 Flower Street P.O. Box 25020 Glendale, CA 91221 [email protected] Abstract Squeak is an open, highly-portable Smalltalk implementation whose virtual machine is written entirely in Smalltalk, making it easy to debug, analyze, and change. To achieve practical performance, a translator produces an equivalent C program whose performance is comparable to commercial Smalltalks. Other noteworthy aspects of Squeak include: a compact object format that typically requires only a single word of overhead per object; a simple yet efficient incremental garbage collector for 32-bit direct pointers; efficient bulk- mutation of objects; extensions of BitBlt to handle color of any depth and anti-aliased image rotation and scaling; and real-time sound and music synthesis written entirely in Smalltalk. Overview Squeak is a modern implementation of Smalltalk-80 that is available for free via the Internet, at http://www.research.apple.com/research/proj/learning_concepts/squeak/ and other sites. It includes platform-independent support for color, sound, and image processing. -
Smalltalk's Influence on Modern Programming
1 Smalltalk’s Influence on Modern Programming Smalltalk’s Influence on Modern Programming Matt Savona. February 1 st , 2008. In September 1972 at Xerox PARC, Alan Kay, Ted Kaeher and Dan Ingalls were discussing programming languages in the hallway of their office building. Ted and Dan had begun to consider how large a language had to be to have “great power.” Alan took a different approach, and “asserted that you could define the "most powerful language in the world" in "a page of code."” Ted and Dan replied, “Put up or shut up” (Kay). And with that, the bet to develop the most powerful language was on. Alan arrived at PARC every morning at 4am for two weeks, and devoted his time from 4am to 8am to the development of the language. That language was Smalltalk. Kay had “originally made the boast because McCarthy's self-describing LISP interpreter was written in itself. It was about "a page", and as far as power goes, LISP was the whole nine- yards for functional languages.” He was sure that he could “do the same for object-oriented languages” and still have a reasonable syntax. By the eighth morning, Kay had a version of Smalltalk developed where “symbols were byte-coded and the receiving of return-values from a send was symmetric” (Kay). Several days later, Dan Ingalls had coded Kay’s scheme in BASIC, added a “token scanner”, “list maker” and many other features. “Over the next ten years he made at least 80 major releases of various flavors of Smalltalk” (Kay). -
Cross-Language Interop Poster
Low Cognitive Overhead Bridging "Interoperability isn't just a technical problem, it's also a user interface problem. We have to make it easy to call between languages, so that users can The demo shown at FOSDEM always pick the most appropriate tool for the job at hand." example [ this year showed fully dynamic "This shows how to call a C function from Smalltalk" development spanning C objc_setAssociatedObject: { Objective-C and Smalltalk. The self. 42. developer can inspect the ’fishes’. existing class hierarchy and C enumValue: OBJC_ASSOCIATION_ASSIGN }. the code for any methods "Note how C enumerations can be accessed. When encountering this construct, the Pragmatic Smalltalk compiler will generate exactly the same code as an implemented in Smalltalk. It Objective-C compiler would for this line: is also possible to add, modify, objc_setAssociatedObject(self, 42, @"fishes", OBJC_ASSOCIATION_ASSIGN); or replace methods, add It will get the types for the function by parsing the header and automatically map Smalltalk types to C and Objective-C types. The instance variables and classes Easy Development programmer doesn't need to write any bridging or foreign function interface at run time. Invoking a code." nonexistent class or method (C objc_getAssociatedObject: {self . 42 }) log. ] pops up a dialog asking the user to implement it, all from within a running app. The final version is statically compiled, with no explicit user Cross-Language Interoperability for intervention required. Fast, Easy, and Maintainable Code David Chisnall The World Today: But I wanted to use the But libfoo is C, libbar Frobnicator framework, and it's I have a great idea is C++, and I want to only for Java. -
Smalltalk Language Mapping Specification
Smalltalk Language Mapping Specification New Edition: June 1999 Copyright 1995, 1996 BNR Europe Ltd. Copyright 1998, Borland International Copyright 1991, 1992, 1995, 1996 Digital Equipment Corporation Copyright 1995, 1996 Expersoft Corporation Copyright 1996, 1997 FUJITSU LIMITED Copyright 1996 Genesis Development Corporation Copyright 1989, 1990, 1991, 1992, 1995, 1996 Hewlett-Packard Company Copyright 1991, 1992, 1995, 1996 HyperDesk Corporation Copyright 1998 Inprise Corporation Copyright 1996, 1997 International Business Machines Corporation Copyright 1995, 1996 ICL, plc Copyright 1995, 1996 IONA Technologies, Ltd. Copyright 1996, 1997 Micro Focus Limited Copyright 1991, 1992, 1995, 1996 NCR Corporation Copyright 1995, 1996 Novell USG Copyright 1991,1992, 1995, 1996 by Object Design, Inc. Copyright 1991, 1992, 1995, 1996 Object Management Group, Inc. Copyright 1996 Siemens Nixdorf Informationssysteme AG Copyright 1991, 1992, 1995, 1996 Sun Microsystems, Inc. Copyright 1995, 1996 SunSoft, Inc. Copyright 1996 Sybase, Inc. Copyright 1998 Telefónica Investigación y Desarrollo S.A. Unipersonal Copyright 1996 Visual Edge Software, Ltd. The companies listed above have granted to the Object Management Group, Inc. (OMG) a nonexclusive, royalty-free, paid up, worldwide license to copy and distribute this document and to modify this document and distribute copies of the modified ver- sion. Each of the copyright holders listed above has agreed that no person shall be deemed to have infringed the copyright in the included material of any such copyright holder by reason of having used the specification set forth herein or having con- formed any computer software to the specification. PATENT The attention of adopters is directed to the possibility that compliance with or adoption of OMG specifications may require use of an invention covered by patent rights. -
Dynamic Object-Oriented Programming with Smalltalk
Dynamic Object-Oriented Programming with Smalltalk 1. Introduction Prof. O. Nierstrasz Autumn Semester 2009 LECTURE TITLE What is surprising about Smalltalk > Everything is an object > Everything happens by sending messages > All the source code is there all the time > You can't lose code > You can change everything > You can change things without restarting the system > The Debugger is your Friend © Oscar Nierstrasz 2 ST — Introduction Why Smalltalk? > Pure object-oriented language and environment — “Everything is an object” > Origin of many innovations in OO development — RDD, IDE, MVC, XUnit … > Improves on many of its successors — Fully interactive and dynamic © Oscar Nierstrasz 1.3 ST — Introduction What is Smalltalk? > Pure OO language — Single inheritance — Dynamically typed > Language and environment — Guiding principle: “Everything is an Object” — Class browser, debugger, inspector, … — Mature class library and tools > Virtual machine — Objects exist in a persistent image [+ changes] — Incremental compilation © Oscar Nierstrasz 1.4 ST — Introduction Smalltalk vs. C++ vs. Java Smalltalk C++ Java Object model Pure Hybrid Hybrid Garbage collection Automatic Manual Automatic Inheritance Single Multiple Single Types Dynamic Static Static Reflection Fully reflective Introspection Introspection Semaphores, Some libraries Monitors Concurrency Monitors Categories, Namespaces Packages Modules namespaces © Oscar Nierstrasz 1.5 ST — Introduction Smalltalk: a State of Mind > Small and uniform language — Syntax fits on one sheet of paper > -
Alexey Patrushev Analysis of Software Engineering Data with Self-Organizing Maps
ALEXEY PATRUSHEV ANALYSIS OF SOFTWARE ENGINEERING DATA WITH SELF-ORGANIZING MAPS Master of Science thesis Examiner: prof. Kari Systä Examiner and topic approved by the Faculty Council of the Faculty of Computing and Electrical Engineering on 4th May 2016 i ABSTRACT Alexey Patrushev: Analysis of software engineering data with self-organizing maps, Tampere University of Technology Master of Science Thesis, 72 pages, 17 Appendix pages January 2016 Master’s Degree Programme in Information Technology Major: Pervasive Systems Examiner: Professor Kari Systä Keywords: Self-Organizing Maps, Software Engineering Data, Machine Learning Nowadays software developers have tools that help to assist them during development and management processes of software products. These tools store large amount of Software Engineering data resulted from these processes. Analysis of the data can reveal valuable information about project performance and discover useful business patterns used during development. This information can be utilized to find projects where teams have some management problems and help to improve situation. Currently existing methods in the field have applicability limitations, because they require an expert knowledge for evaluation and are not capable to deal with large number of projects. In this thesis, we will explore possibility to apply Machine Learning methods to analysis of software engineering data. Machine Learning methods are capable to build a model from sample inputs and produce data-driven predictions. They have been gaining popularity over the last decades and show promising results in applications, where human expertise was traditionally used. In this work, we attempt to extract and analyze software project management patterns from software engineering data stored in the GitHub repositories. -
Prioritizing Pull Requests
Prioritizing pull requests Version of June 17, 2015 Erik van der Veen Prioritizing pull requests THESIS submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in COMPUTER SCIENCE by Erik van der Veen born in Voorburg, the Netherlands Software Engineering Research Group Q42 Department of Software Technology Waldorpstraat 17F Faculty EEMCS, Delft University of Technology 2521 CA Delft, the Netherlands The Hague, the Netherlands www.ewi.tudelft.nl www.q42.com c 2014 Erik van der Veen. Cover picture: Finding the pull request that needs the most attention. Prioritizing pull requests Author: Erik van der Veen Student id: 1509381 Email: [email protected] Abstract Previous work showed that in the pull-based development model integrators face challenges with regard to prioritizing work in the face of multiple concurrent pull requests. We identified the manual prioritization heuristics applied by integrators and ex- tracted features from these heuristics. The features are used to train a machine learning model, which is capable of predicting a pull request’s importance. The importance is then used to create a prioritized order of the pull requests. Our main contribution is the design and initial implementation of a prototype service, called PRioritizer, which automatically prioritizes pull requests. The service works like a priority inbox for pull requests, recommending the top pull requests the project owner should focus on. It keeps the pull request list up-to-date when pull requests are merged or closed. In addition, the service provides functionality that GitHub is currently lacking. We implemented pairwise pull request conflict detection and several new filter and sorting options e.g. -
Smalltalk Reading List
Smalltalkreading list Smalltalk introduced the world to Object Much of the genesis of Smalltalk is explained Smalltalk was created over the course of a For the history in Silicon Valley leading up to Oriented programming, a way of representing in Alan Kay’s Personal Computer for Children decade starting in 1970 at Xerox’s Palo Alto the inspiration and creation of Smalltalk, see software as a network of interconnected and of All Ages wherein he describes the Research Center (better known as Xerox PARC) John Markoff’s What the Dormouse Said. intercommunicating little computers. It has Dynabook computer. The Dynabook was to be by the company’s Learning Research Group. influenced nearly every programming a personal dynamic computer, with a flat language since, including Objective C, Java, screen and a keyboard (today’s iPads bear a When people think about Smalltalk as a and Swift. striking resemblance). professional programming language it’s almost always Smalltalk-80 (released in This reading list contains books, essays, and The Dynabook’s system software was 1980) they’re thinking about, but in fact videos detailing the time and place from intended to be built and modified by anyone, Smalltalk had dozens of versions and which Smalltalk emerged, the mindsets and for books and music, but more importantly for revisions in the preceding decade. visions of its creators, and the influences understanding complex systems. Smalltalk has had on computer systems and Smalltalk was originally intended as a their programming languages. The Smalltalk software and hardware that medium of expression, and not as a For the history of Xerox PARC in the decade came out of Xerox PARC were in direct pursuit professional developer tool until much later. -
Poli12-Bootstrappingsmalltalk-SCP
Bootstrapping Reflective Systems: The Case of Pharo G. Polito1,2,∗, S. Ducasse1, L. Fabresse2, N. Bouraqadi2, B. van Ryseghem1 Abstract Bootstrapping is a technique commonly known by its usage in language definition by the introduction of a compiler written in the same language it compiles. This process is important to understand and modify the definition of a given language using the same language, taking benefit of the abstractions and expression power it provides. A bootstrap, then, supports the evolution of a language. However, the infrastructure of reflective systems like Smalltalk includes, in addition to a compiler, an environment with several self-references. A reflective system bootstrap should consider all its infrastructural components. In this paper, we propose a definition of bootstrap for object-oriented reflective systems, we describe the architecture and components it should contain and we analyze the challenges it has to overcome. Finally, we present a reference bootstrap process for a reflective system and Hazelnut, its implementation for bootstrapping the Pharo Smalltalk-inspired system. Keywords: Object-Oriented Programming and Design, Bootstrap, Smalltalk, Software Evolution 1. Introduction Reflective systems are those that reason about and act upon themselves [21]. A causal connection exists between the program and its representation inside the program itself as a meta-program [16]. This reflective architecture introduces self-references: an object-oriented system is composed by objects, which are instances of classes, which are also objects, and so on. These self-references, also known as meta-circularities [6], allow the manipulation of several meta-levels on one infrastructure. Reflective systems traditionally modify their self-representation to evolve and define new abstractions. -
Proceedings.Pdf
Goals and scopes •The goals of the workshop is to create a forum around advances or experience in Smalltalk and to trigger discussions and exchanges of ideas. Participants are invited to submit research articles. We will not enforce any length restriction. However we expect papers of two kinds: –Short position papers describing emerging ideas. –Long research papers with deeper description of experiments and of research results. •We welcome contributions on all aspects, theoretical as well as practical, of Smalltalk related topics such as: –Aspect-oriented programming, –Design patterns, –Experience reports, –Frameworks, –Implementation, –new dialects or languages implemented in Smalltalk, –Interaction with other languages, –Meta-programming and Meta-modeling, –Tools Publication •Both submissions and final papers must be prepared using the ACM SIGPLAN 10 point format. Templates for Word and LaTeX are available at http://www.acm.org/sigs/sigplan/authorInformation.htm •Authors of the best accepted papers will also be invited to submit extended versions for publication in a special issue of Elsevier "Science of Computer Programming: Methods of Software Design: Techniques and Applications" •Please submit your paper through EasyChair on http://www.easychair.org/conferences/?conf=iwst2012 Program Chairs •Loïc Lagadec Lab-STICC, UBO, France •Alain Plantec, Lab-STICC, UBO, France Program Committee •Gabriela Arevalo, Universidad Nacional de Quilmes, Agentina •Alexandre Bergel University of Chile •Andrew P. Black Portland State University, US •Marcus -
How to Identify Class Comment Types? a Multi-Language Approach for Class Comment Classification
How to Identify Class Comment Types? A Multi-language Approach for Class Comment Classification Pooja Rania, Sebastiano Panichellab, Manuel Leuenbergera, Andrea Di Sorboc, Oscar Nierstrasza aSoftware Composition Group, University of Bern, Switzerland bZurich University of Applied Science, Switzerland cDepartment of Engineering, University of Sannio, Italy Abstract Most software maintenance and evolution tasks require developers to understand the source code of their software systems. Software developers usually inspect class comments to gain knowledge about program behavior, regardless of the programming language they are using. Unfortunately, (i) different programming languages present language-specific code commenting notations and guidelines; and (ii) the source code of software projects often lacks comments that adequately describe the class behavior, which complicates program comprehension and evolution activities. To handle these challenges, this paper investigates the different language-specific class commenting practices of three program- ming languages: Python, Java, and Smalltalk. In particular, we systematically analyze the similarities and differences of the information types found in class comments of projects developed in these languages. We propose an approach that leverages two techniques — namely Natural Language Processing and Text Analysis — to auto- matically identify class comment types, i.e., the specific types of semantic information found in class comments. To the best of our knowledge, no previous work has provided a comprehensive taxonomy of class comment types for these three programming languages with the help of a common automated approach. Our results confirm that our approach can classify frequent class com- ment information types with high accuracy for the Python, Java, and Smalltalk programming languages. We believe this work can help in monitoring and assessing the quality and evolution of code comments in different programming languages, and thus support maintenance and evolution tasks. -
Objective-C 2.0 Essentials Third Edition
Objective-C 2.0 Essentials Third Edition i Objective-C 2.0 Essentials – Third Edition ISBN-13: 978-1480262102 © 2012 Neil Smyth. This book is provided for personal use only. Unauthorized use, reproduction and/or distribution strictly prohibited. All rights reserved. The content of this book is provided for informational purposes only. Neither the publisher nor the author offers any warranties or representation, express or implied, with regard to the accuracy of information contained in this book, nor do they accept any liability for any loss or damage arising from any errors or omissions. This book contains trademarked terms that are used solely for editorial purposes and to the benefit of the respective trademark owner. The terms used within this book are not intended as infringement of any trademarks. Find more eBooks online at http://www.eBookFrenzy.com. Rev. 3.0 ii Table of Contents 1. About Objective-C Essentials ...................................................................................................... 1 1.1 Why are you reading this? .................................................................................................... 1 1.2 Supported Platforms ............................................................................................................. 2 2. The History of Objective-C .......................................................................................................... 3 2.1 The C Programming Language .............................................................................................