DOCSLIB.ORG

Structuring Languages As Object-Oriented Libraries

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Structuring Languages As Object-Oriented Libraries Structuring Languages as Object-Oriented Libraries Structuring Languages as Object-Oriented Libraries ACADEMISCH PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit van Amsterdam op gezag van de Rector Magnificus prof. dr. ir. K. I. J. Maex ten overstaan van een door het College voor Promoties ingestelde commissie, in het openbaar te verdedigen in de Agnietenkapel op donderdag november , te . uur door Pablo Antonio Inostroza Valdera geboren te Concepción, Chili Promotiecommissie Promotores: Prof. Dr. P. Klint Universiteit van Amsterdam Prof. Dr. T. van der Storm Rijksuniversiteit Groningen Overige leden: Prof. Dr. J.A. Bergstra Universiteit van Amsterdam Prof. Dr. B. Combemale University of Toulouse Dr. C. Grelck Universiteit van Amsterdam Prof. Dr. P.D. Mosses Swansea University Dr. B.C.d.S. Oliveira The University of Hong Kong Prof. Dr. M. de Rijke Universiteit van Amsterdam Faculteit der Natuurwetenschappen, Wiskunde en Informatica The work in this thesis has been carried out at Centrum Wiskunde & Informatica (CWI) under the auspices of the research school IPA (Institute for Programming research and Algorith- mics) and has been supported by NWO, in the context of Jacquard Project .. “Next Generation Auditing: Data-Assurance as a Service”. Contents Introduction .Language Libraries . .Object Algebras . .Language Libraries with Object Algebras . .Origins of the Chapters . .Software Artifacts . .Dissertation Structure . Recaf: Java Dialects as Libraries .Introduction . .Overview.................................... .Statement Virtualization . .Full Virtualization . .Implementation of Recaf . .Case Studies . .Discussion . .Related Work . .Conclusion . Tracing Program Transformations with String Origins .Introduction . .String Origins . .Applications of String Origins . .Implementation . .Related Work . .Conclusion . Modular Interpreters with Implicit Context Propagation .Introduction . .Background . v Contents .Implicit Context Propagation . .Working with Lifted Interpretations . .Automating Lifting . .Case study : Extending a DSL for State Machines . .Case Study : Modularizing Featherweight Java . .Performance Overhead of Lifting . .Related Work and Discussion . . Conclusion . JEff: Objects for Effect .Introduction . .JEff: Programming with Objects and Effects . .Dynamic Semantics . .Type System . .Discussion & Related Work . .Conclusion . Conclusion .Recapitulation of Research Questions . .Discussion . .Conclusion . Bibliography Summary Samenvatting Acknowledgments vi 1 Introduction Implementing programming languages is a non-trivial endeavor. A typical language processing pipeline consists of several possibly interdependent components. Thus, if an existing programming language is extended with a new construct, its tooling has to be extended accordingly. A case in point could be adding an async/await mechanism to a Java-like language. This would imply that all the processors of this language will need to be extended to consider the new constructs. It is therefore desirable that one could reuse the implementation of existing processors, extending them in a modular fashion. However, this kind of language extension poses a number of challenges. For instance, a newly introduced feature can demand different context information than the one assumed by the existing processors, or it can interact with the existing features in intricate ways. These scenarios show how complex is to achieve true modular language extensibility. In this thesis we develop techniques to reduce this complexity, contributing to make the implementation of modular languages a reality. The results of this dissertation contribute to the idea of language-oriented pro- gramming [Dmi; FFF+; War], a vision that puts programming languages at the center of the software development practice. Instead of using one general-purpose programming language (GPL), the idea is to represent the diversity of domains that crosscut traditional software development using specialized Domain-Specific Languages (DSL) [Fow; vDKV]. This allows programmers to concentrate on the elements of the domain and their interactions instead of the details about their representation. In language-oriented programming it is essential to have tools and practices that make the development of new languages less costly. In particular, in this thesis we exploit linguistic reuse [Kri] by means of better modularity. We consider linguistic . Introduction reuse as the application of the principles of software reuse to the domain of language development. According to Krueger [Kru], “Software Reuse is the process of creating software systems from existing software rather than building software systems from scratch”. A canonical example of reuse is library-based development. In fact, in McIllroy’s seminal paper on software reuse he presents the vision of a library of reusable components [McI]; software can be thus developed by assembling such components. A software library is a collection of interrelated functions, classes or modules that cover a particular domain or application concern (e.g., accessing the database) and is intended to be reused as is. The main motivation of this thesis is to provide new mechanisms to implement libraries of language fragments. A language fragment is the specification of a language that might or might not be usable on its own, but can be composed with others to form increasingly complex languages. In other words, a language fragment is a module that represents the implementation of part of a language. The essential question that follows is how to define modular and extensible language fragments. One of the keys of the success of object-oriented programming is its support for extensibility via inheritance [Ald]. Statically typed object-oriented languages such as Java or C# support static safe incremental extensibility which enables modular development. In this work we posit the question of how to use object-oriented techniques to implement reusable language fragments. The object algebra pattern [OC], encoded with standard object-oriented features, is a technique in that direction, as it enables incremental extensibility along two axes that fit the language development scenario: to develop a language we can both extend its syntax and add new semantic interpretations. In this thesis we exploit the object algebra pattern to develop modular language components that form libraries of language fragments. We focus our attention on two kinds of libraries. On the one hand, we want to develop extensions of an existing GPL using object algebra-based language fragments, in the spirit of “Growing a Language” [Ste]. On the other hand, we want to assemble several object algebra- based language fragments that can help us to build different languages from scratch, as if these fragments were language LEGO blocks. The next section provides an overview of the idea of language libraries and component-based language specifications, alongside the background on related techniques for language extensibility and language modularity. Section .introduces the central technique that we make use of: object algebras, while Section .describes how we have applied object algebras to develop language libraries, introducing our research questions and how they correspond to the chapters in this thesis. Furthermore, related work that is specific to each research question is also discussed. In Section . we list our contributions in terms of peer-reviewed publications. Section .presents .. Language Libraries the software artifacts produced in the context of this thesis. Finally Section . describes the structure of this dissertation. Language Libraries The idea of component-based language development has originated work in different communities. In [TSC+], for example, the authors coin the concept of “Language as Libraries” and illustrate it with the Racket language. Racket programmers can write language modules that reuse the base-level meta-infrastructure by having access to a well-defined interface to the static semantics. These modules themselves are written in Racket supporting the argument that writing a language is equivalent to writing a library in the base language, instead of more complex approaches such as extensible compilers [NCM]. Another embodiment of the idea of language libraries is SugarJ [ERK+], a Java-like language in which libraries are just like regular Java libraries together with syntactic sugar definitions to cater for extensible syntax. On the more formal side, Bergstra et al. propose an axiomatic algebraic calculus of modules to dissect the essence of composition [BHK]. More pragmatically, Heering and Klint consider a library of reusable semantic components as an essential element of Language Design Assistants [HK]. In [CMS+; CMT] Churchill et al. propose fundamental constructs (fun- cons), a fixed set of reusable components of semantic specifications defined using I-MSOS [MN], an improved, modular variant of Structural Operational Semantics. Using funcons as basic building blocks, one can specify arbitrary compositions that provide the specification of complex general-purpose languages. In this dissertation, a language library is a library of language fragments written in an object-oriented host language. The basic mechanism for implementing the idea of language libraries is language composition. It is therefore necessary to establish some basic terminology in this regard. In algebraic terms, if we have two modular definitions for language
Load more

Recommended publications
  • Comparative Studies of Programming Languages; Course Lecture Notes
    Comparative Studies of Programming Languages, COMP6411 Lecture Notes, Revision 1.9 Joey Paquet Serguei A. Mokhov (Eds.) August 5, 2010 arXiv:1007.2123v6 [cs.PL] 4 Aug 2010 2 Preface Lecture notes for the Comparative Studies of Programming Languages course, COMP6411, taught at the Department of Computer Science and Software Engineering, Faculty of Engineering and Computer Science, Concordia University, Montreal, QC, Canada. These notes include a compiled book of primarily related articles from the Wikipedia, the Free Encyclopedia [24], as well as Comparative Programming Languages book [7] and other resources, including our own. The original notes were compiled by Dr. Paquet [14] 3 4 Contents 1 Brief History and Genealogy of Programming Languages 7 1.1 Introduction . 7 1.1.1 Subreferences . 7 1.2 History . 7 1.2.1 Pre-computer era . 7 1.2.2 Subreferences . 8 1.2.3 Early computer era . 8 1.2.4 Subreferences . 8 1.2.5 Modern/Structured programming languages . 9 1.3 References . 19 2 Programming Paradigms 21 2.1 Introduction . 21 2.2 History . 21 2.2.1 Low-level: binary, assembly . 21 2.2.2 Procedural programming . 22 2.2.3 Object-oriented programming . 23 2.2.4 Declarative programming . 27 3 Program Evaluation 33 3.1 Program analysis and translation phases . 33 3.1.1 Front end . 33 3.1.2 Back end . 34 3.2 Compilation vs. interpretation . 34 3.2.1 Compilation . 34 3.2.2 Interpretation . 36 3.2.3 Subreferences . 37 3.3 Type System . 38 3.3.1 Type checking . 38 3.4 Memory management .
    [Show full text]
  • Cross-Platform Language Design
    Cross-Platform Language Design THIS IS A TEMPORARY TITLE PAGE It will be replaced for the final print by a version provided by the service academique. Thèse n. 1234 2011 présentée le 11 Juin 2018 à la Faculté Informatique et Communications Laboratoire de Méthodes de Programmation 1 programme doctoral en Informatique et Communications École Polytechnique Fédérale de Lausanne pour l’obtention du grade de Docteur ès Sciences par Sébastien Doeraene acceptée sur proposition du jury: Prof James Larus, président du jury Prof Martin Odersky, directeur de thèse Prof Edouard Bugnion, rapporteur Dr Andreas Rossberg, rapporteur Prof Peter Van Roy, rapporteur Lausanne, EPFL, 2018 It is better to repent a sin than regret the loss of a pleasure. — Oscar Wilde Acknowledgments Although there is only one name written in a large font on the front page, there are many people without which this thesis would never have happened, or would not have been quite the same. Five years is a long time, during which I had the privilege to work, discuss, sing, learn and have fun with many people. I am afraid to make a list, for I am sure I will forget some. Nevertheless, I will try my best. First, I would like to thank my advisor, Martin Odersky, for giving me the opportunity to fulfill a dream, that of being part of the design and development team of my favorite programming language. Many thanks for letting me explore the design of Scala.js in my own way, while at the same time always being there when I needed him.
    [Show full text]
  • Behavioral Types in Programming Languages
    Behavioral Types in Programming Languages Behavioral Types in Programming Languages iv Davide Ancona, DIBRIS, Università di Genova, Italy Viviana Bono, Dipartimento di Informatica, Università di Torino, Italy Mario Bravetti, Università di Bologna, Italy / INRIA, France Joana Campos, LaSIGE, Faculdade de Ciências, Universidade de Lisboa, Portugal Giuseppe Castagna, CNRS, IRIF, Univ Paris Diderot, Sorbonne Paris Cité, Paris, France Pierre-Malo Deniélou, Royal Holloway, University of London, UK Simon J. Gay, School of Computing Science, University of Glasgow, UK Nils Gesbert, Université Grenoble Alpes, France Elena Giachino, Università di Bologna, Italy / INRIA, France Raymond Hu, Department of Computing, Imperial College London, UK Einar Broch Johnsen, Institutt for informatikk, Universitetet i Oslo, Norway Francisco Martins, LaSIGE, Faculdade de Ciências, Universidade de Lisboa, Portugal Viviana Mascardi, DIBRIS, Università di Genova, Italy Fabrizio Montesi, University of Southern Denmark Rumyana Neykova, Department of Computing, Imperial College London, UK Nicholas Ng, Department of Computing, Imperial College London, UK Luca Padovani, Dipartimento di Informatica, Università di Torino, Italy Vasco T. Vasconcelos, LaSIGE, Faculdade de Ciências, Universidade de Lisboa, Portugal Nobuko Yoshida, Department of Computing, Imperial College London, UK Boston — Delft Foundations and Trends R in Programming Languages Published, sold and distributed by: now Publishers Inc. PO Box 1024 Hanover, MA 02339 United States Tel. +1-781-985-4510 www.nowpublishers.com [email protected] Outside North America: now Publishers Inc. PO Box 179 2600 AD Delft The Netherlands Tel. +31-6-51115274 The preferred citation for this publication is D. Ancona et al.. Behavioral Types in Programming Languages. Foundations and Trends R in Programming Languages, vol. 3, no.
    [Show full text]
  • Composable Compilers: Evolution Toward a Practical Reality
    COMPOSABLE COMPILERS: EVOLUTION TOWARD A PRACTICAL REALITY A Dissertation Presented to the Faculty of the Graduate School of Cornell University in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Chinawat Isradisaikul August 2017 c 2017 Chinawat Isradisaikul COMPOSABLE COMPILERS: EVOLUTION TOWARD A PRACTICAL REALITY Chinawat Isradisaikul, Ph.D. Cornell University 2017 The ability to add new features to programming languages is essential for language design experimentation and domain-specific developments, but implementing and maintaining small language extensions in traditional compilers remain a challenge. General-purpose programming languages do not have desired mechanisms to integrate small, indepen- dently developed extensions into a working programming language. At the same time, domain-specific languages that support such integration struggle to gain popularity in the programming language community. More language mechanisms and tools are needed as a middle ground so that a broader range of programmers can implement, maintain, and combine compilers for individual language features more easily. At the heart of compiler construction, new design patterns are proposed to allow compilers to be extended in a modular way and to be merged with little effort. These design patterns, implementable in a mainstream programming language, encode dynamic relationships between node types in abstract syntax trees (ASTs) so that inheritance in object-oriented programming still works over the course of language evolution. A new AST representation lets a single AST be viewed as different programs for different languages. Compiler passes are language-neutral, making translations reusable and composable. At the front end, engineering language syntax can be a painstaking process, espe- cially when individual language syntaxes start to interact.
    [Show full text]
  • A Core Calculus of Metaclasses
    A Core Calculus of Metaclasses Sam Tobin-Hochstadt Eric Allen Northeastern University Sun Microsystems Laboratories [email protected] [email protected] Abstract see the problem, consider a system with a class Eagle and Metaclasses provide a useful mechanism for abstraction in an instance Harry. The static type system can ensure that object-oriented languages. But most languages that support any messages that Harry responds to are also understood by metaclasses impose severe restrictions on their use. Typi- any other instance of Eagle. cally, a metaclass is allowed to have only a single instance However, even in a language where classes can have static and all metaclasses are required to share a common super- methods, the desired relationships cannot be expressed. For class [6]. In addition, few languages that support metaclasses example, in such a language, we can write the expression include a static type system, and none include a type system Eagle.isEndangered() provided that Eagle has the ap- with nominal subtyping (i.e., subtyping as defined in lan- propriate static method. Such a method is appropriate for guages such as the JavaTM Programming Language or C#). any class that is a species. However, if Salmon is another To elucidate the structure of metaclasses and their rela- class in our system, our type system provides us no way of tionship with static types, we present a core calculus for a requiring that it also have an isEndangered method. This nominally typed object-oriented language with metaclasses is because we cannot classify both Salmon and Eagle, when and prove type soundness over this core.
    [Show full text]
  • A History of Clojure
    A History of Clojure RICH HICKEY, Cognitect, Inc., USA Shepherd: Mira Mezini, Technische Universität Darmstadt, Germany Clojure was designed to be a general-purpose, practical functional language, suitable for use by professionals wherever its host language, e.g., Java, would be. Initially designed in 2005 and released in 2007, Clojure is a dialect of Lisp, but is not a direct descendant of any prior Lisp. It complements programming with pure functions of immutable data with concurrency-safe state management constructs that support writing correct multithreaded programs without the complexity of mutex locks. Clojure is intentionally hosted, in that it compiles to and runs on the runtime of another language, such as the JVM. This is more than an implementation strategy; numerous features ensure that programs written in Clojure can leverage and interoperate with the libraries of the host language directly and efficiently. In spite of combining two (at the time) rather unpopular ideas, functional programming and Lisp, Clojure has since seen adoption in industries as diverse as finance, climate science, retail, databases, analytics, publishing, healthcare, advertising and genomics, and by consultancies and startups worldwide, much to the career-altering surprise of its author. Most of the ideas in Clojure were not novel, but their combination puts Clojure in a unique spot in language design (functional, hosted, Lisp). This paper recounts the motivation behind the initial development of Clojure and the rationale for various design decisions and language constructs. It then covers its evolution subsequent to release and adoption. CCS Concepts: • Software and its engineering ! General programming languages; • Social and pro- fessional topics ! History of programming languages.
    [Show full text]
  • Behavioral Types in Programming Languages
    Foundations and Trends R in Programming Languages Vol. 3, No. 2-3 (2016) 95–230 c 2016 D. Ancona et al. DOI: 10.1561/2500000031 Behavioral Types in Programming Languages Davide Ancona, DIBRIS, Università di Genova, Italy Viviana Bono, Dipartimento di Informatica, Università di Torino, Italy Mario Bravetti, Università di Bologna, Italy / INRIA, France Joana Campos, LaSIGE, Faculdade de Ciências, Univ de Lisboa, Portugal Giuseppe Castagna, CNRS, IRIF, Univ Paris Diderot, Sorbonne Paris Cité, France Pierre-Malo Deniélou, Royal Holloway, University of London, UK Simon J. Gay, School of Computing Science, University of Glasgow, UK Nils Gesbert, Université Grenoble Alpes, France Elena Giachino, Università di Bologna, Italy / INRIA, France Raymond Hu, Department of Computing, Imperial College London, UK Einar Broch Johnsen, Institutt for informatikk, Universitetet i Oslo, Norway Francisco Martins, LaSIGE, Faculdade de Ciências, Univ de Lisboa, Portugal Viviana Mascardi, DIBRIS, Università di Genova, Italy Fabrizio Montesi, University of Southern Denmark Rumyana Neykova, Department of Computing, Imperial College London, UK Nicholas Ng, Department of Computing, Imperial College London, UK Luca Padovani, Dipartimento di Informatica, Università di Torino, Italy Vasco T. Vasconcelos, LaSIGE, Faculdade de Ciências, Univ de Lisboa, Portugal Nobuko Yoshida, Department of Computing, Imperial College London, UK Contents 1 Introduction 96 2 Object-Oriented Languages 105 2.1 Session Types in Core Object-Oriented Languages . 106 2.2 Behavioral Types in Java-like Languages . 121 2.3 Typestate . 134 2.4 Related Work . 139 3 Functional Languages 140 3.1 Effects for Session Type Checking . 141 3.2 Sessions and Explicit Continuations . 143 3.3 Monadic Approaches to Session Type Checking .
    [Show full text]
  • Good Advice for Type-Directed Programming
    Good Advice for Type-directed Programming Aspect-oriented Programming and Extensible Generic Functions Geoffrey Washburn Stephanie Weirich University of Pennsylvania {geoffw,sweirich}@cis.upenn.edu ABSTRACT of type-directed combinators to “scrap” this boilerplate. For Type-directed programming is an important idiom for soft- example, L¨ammeland Peyton Jones’s Haskell library pro- ware design. In type-directed programming the behavior of vides a combinator called gmapQ that maps a query over programs is guided by the type structure of data. It makes an arbitrary value’s children returning a list of the results. it possible to implement many sorts of operations, such as Using gmapQ it becomes trivial to implement a type-directed serialization, traversals, and queries, only once and without function, gsize, to compute the size of an arbitrary value. needing to continually revise their implementation as new gsize :: Data a => a -> Int data types are defined. gsize x = 1 + sum (gmapQ gsize x) Type-directed programming is the basis for recent research into “scrapping” tedious boilerplate code that arises in func- However, this line of research focused on closed type- tional programming with algebraic data types. This research directed functions. Closed type-directed functions require has primarily focused on writing type-directed functions that that all cases be defined in advance. Consequently, if the are closed to extension. However, L¨ammel and Peyton Jones programmer wanted gsize to behave in a specialized fashion recently developed a technique for writing openly extensible for one of their data types, they would need to edit the type-directed functions in Haskell by making clever use of definition of gmapQ.
    [Show full text]
  • Functional Programming Patterns in Scala and Clojure Write Lean Programs for the JVM
    Early Praise for Functional Programming Patterns This book is an absolute gem and should be required reading for anybody looking to transition from OO to FP. It is an extremely well-built safety rope for those crossing the bridge between two very different worlds. Consider this mandatory reading. ➤ Colin Yates, technical team leader at QFI Consulting, LLP This book sticks to the meat and potatoes of what functional programming can do for the object-oriented JVM programmer. The functional patterns are sectioned in the back of the book separate from the functional replacements of the object-oriented patterns, making the book handy reference material. As a Scala programmer, I even picked up some new tricks along the read. ➤ Justin James, developer with Full Stack Apps This book is good for those who have dabbled a bit in Clojure or Scala but are not really comfortable with it; the ideal audience is seasoned OO programmers looking to adopt a functional style, as it gives those programmers a guide for transitioning away from the patterns they are comfortable with. ➤ Rod Hilton, Java developer and PhD candidate at the University of Colorado Functional Programming Patterns in Scala and Clojure Write Lean Programs for the JVM Michael Bevilacqua-Linn The Pragmatic Bookshelf Dallas, Texas • Raleigh, North Carolina Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and The Pragmatic Programmers, LLC was aware of a trademark claim, the designations have been printed in initial capital letters or in all capitals.
    [Show full text]
  • Semantic Types for Class-Based Objects
    Imperial College London Department of Computing Semantic Types for Class-based Objects Reuben N. S. Rowe July 2012 Supervised by Dr. Steffen van Bakel Submitted in part fulfilment of the requirements for the degree of Doctor of Philosophy in Computing of Imperial College London and the Diploma of Imperial College London 1 Abstract We investigate semantics-based type assignment for class-based object-oriented programming. Our mo- tivation is developing a theoretical basis for practical, expressive, type-based analysis of the functional behaviour of object-oriented programs. We focus our research using Featherweight Java, studying two notions of type assignment:- one using intersection types, the other a ‘logical’ restriction of recursive types. We extend to the object-oriented setting some existing results for intersection type systems. In do- ing so, we contribute to the study of denotational semantics for object-oriented languages. We define a model for Featherweight Java based on approximation, which we relate to our intersection type system via an Approximation Result, proved using a notion of reduction on typing derivations that we show to be strongly normalising. We consider restrictions of our system for which type assignment is decid- able, observing that the implicit recursion present in the class mechanism is a limiting factor in making practical use of the expressive power of intersection types. To overcome this, we consider type assignment based on recursive types. Such types traditionally suffer from the inability to characterise convergence, a key element of our approach. To obtain a se- mantic system of recursive types for Featherweight Java we study Nakano’s systems, whose key feature is an approximation modality which leads to a ‘logical’ system expressing both functional behaviour and convergence.
    [Show full text]
  • Pluggable Type Systems
    Pluggable Type Systems Gilad Bracha Copyright Gilad Bracha 2002-2004 The Paradox of Type Systems • Type systems help reliability and security by mechanically proving program properties • Type systems hurt reliability and security by making things complex and brittle Copyright Gilad Bracha 2003-2004 Mandatory Typing Well known advantages: • Machine-checkable documentation • Types provide conceptual framework • Early error detection • Performance advantages Copyright Gilad Bracha 2002-2004 Mandatory Typing Disadvantages: • Brittleness/Rigidity • Lack of expressive power Copyright Gilad Bracha 2002-2004 Mandatory Typing Disadvantages: • Brittleness/Rigidity • Lack of expressive power Copyright Gilad Bracha 2002-2004 Brittleness of Mandatory Typing • Security/Robustness - as strong as the type system/the weakest link • Persistence/Serialization • Type systems for VM and language collide Copyright Gilad Bracha 2002-2004 Brittleness of Mandatory Typing • Security/Robustness - as strong as the type system/the weakest link • Persistence/Serialization • Type systems for VM and language collide Copyright Gilad Bracha 2002-2004 How Mandatory Typing Undermines Security • Once a mandatory type system is in place, people rely on it for: • Optimization • Security Guarantees • If type system fails, behavior is completely undefined Copyright Gilad Bracha 2002-2004 Example: Class Loaders Class loading becomes incredibly subtle (cf. Liang and Bracha, OOPSLA 98) • Class loaders define name spaces for types • JVM has nominal type system • Inconsistent namespaces mean inconsistent types • Failure to detect inconsistencies across class loaders leads to catastrophic failure (forgeable pointers, privacy violations etc.) Copyright Gilad Bracha 2002-2004 Example: Class Loaders class A { C getC() { return new B().getC();}} class B { C getC() { return new C();}} • A and B defined in different, but overlapping namespaces N1 and N2.
    [Show full text]
  • Internal and External Mechanisms for Extending Programming Languages
    Internal and External Mechanisms for Extending Programming Languages Keren Lenz Technion - Computer Science Department - Ph.D. Thesis PHD-2013-03 - 2013 Technion - Computer Science Department - Ph.D. Thesis PHD-2013-03 - 2013 Internal and External Mechanisms for Extending Programming Languages Research Thesis Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Keren Lenz Submitted to the Senate of the Technion — Israel Institute of Technology Kislev 5773 Haifa November 2012 Technion - Computer Science Department - Ph.D. Thesis PHD-2013-03 - 2013 Technion - Computer Science Department - Ph.D. Thesis PHD-2013-03 - 2013 The research thesis was done under the supervision of Prof. Joseph (Yossi) Gil in the Computer Science Department. First and foremost, I would like to express my gratitude to my advisor, Prof. Yossi Gil. He has patiently guided me in my journey as a new researcher, providing me with valuable insights and practical guidance, as well as encouragement. I would like to thank my parents, Hava and Avishay Golz, for years of dedica- tion and devotion and mainly for bestowing me with education as a key principle since early age. Special thanks go to my brother, Omer, for his incredible support and help in parts of this research. Finally, I am indebted to my beloved husband Oron, for standing beside me every step of the way; and to my Children, Amit, Roy and Ido, for making me happy. The generous financial support of the Technion, the Harbor fund, and IBM’s PhD Fellowship program is gratefully acknowledged. Technion - Computer Science Department - Ph.D. Thesis PHD-2013-03 - 2013 Technion - Computer Science Department - Ph.D.
    [Show full text]