DOCSLIB.ORG

Automatic Synthesis of Component & Connector-Software Architectures

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Automatic Synthesis of Component & Connector-Software Architectures Automatic Synthesis of Component & Connector- Software Architectures with Bounded Combinatory Logic Dissertation zur Erlangung des Grades eines Doktors der Naturwissenschaften der Technischen Universit¨atDortmund an der Fakult¨atf¨urInformatik von Boris D¨udder Dortmund 2014 Tag der m¨undlichen Pr¨ufung: 25. August 2014 Dekan: Prof. Dr.-Ing. Gernot A. Fink Gutachter: Prof. Dr. Jakob Rehof Prof. Ph.D. Fritz Henglein Acknowledgment Foremost, I would like to express my sincere gratitude to my advisor Prof. Dr. Jakob Rehof for the continuous support of my dissertation and research, for his inspiration, patience, motivation, enthusiasm, and profound knowledge. His guidance helped me in all the time of my research and of writing of this thesis. I could not have imagined having a better advisor and mentor for my research and dissertation. Ditto, I would like to thank the rest of my promotions committee: Prof. Ph.D. Fritz Henglein, Prof. Dr. Bernhard Steffen, and Dr. Doris Schmed- ding, for their encouragement, insightful comments, and hard but constructive questions. My sincere thanks also goes to Dr. Moritz Martens, Prof. Dr. Dietmar Jan- nach, Prof. Dr. Pawe lUrzyczyn, Prof. Dr. Ugo de'Liguoro, Prof. Dr. Mari- angiola Dezani-Ciancaglini, Zani Sarkisya, Anna Vasileva, Jan Bessai, and Andrej Dudenhefner, for working with me on various exciting projects and also to Ute Joschko for her help. Thanks are also due to my wife Olga, my brother Gordon, and my parents. Abstract Combinatory logic synthesis is a new type-based approach towards auto- matic synthesis of software from components in a repository. In this thesis we show how the type-based approach can naturally be used to exploit taxonomic conceptual structures in software architectures and component repositories to enable automatic composition and configuration of components, and also code generation, by associating taxonomic concepts to architectural building blocks such as, in particular, software connectors. Components of a repository are exposed for synthesis as typed combinators, where intersection types are used to represent concepts that specify intended usage and functionality of a component. An algorithm for solving the type inhabitation problem in combinatory logic | does there exist a composition of combinators with a given type? | is then used to automate the retrieval, composition, and configuration of suitable building blocks with respect to a goal specification. Since type inhabitation has high computational complexity, heuristic opti- mizations for the inhabitation algorithm are essential for making the approach practical. We discuss particularly important (theoretical and pragmatic) opti- mization strategies and evaluate them by experiments. Furthermore, we apply this synthesis approach to define a method for software connector synthesis for realistic software architectures based on a type theoretic model. We conduct experiments with a rapid prototyping tool that employs this method on complex concrete ERP- and e-Commerce-systems and discuss the results. Contents 1 Introduction 1 1.1 Composition Synthesis and Inhabitation . .3 1.2 Combinatory Logic Synthesis . .5 1.3 Example for Combinatory Logic Synthesis . .7 1.4 Combinatory Logic Synthesis and Software Connectors . .9 1.5 Why does this problem matter? . 12 1.6 Synthesizing from Components . 13 1.7 Contributions . 13 1.7.1 Publications & Delimitations . 13 1.7.2 Theoretical Contributions . 15 1.7.3 Technical Contributions . 15 1.7.4 Interconnections between Contributions . 16 1.8 Organization . 17 2 Software Architecture 19 2.1 What is Software Architecture? . 19 2.2 Describing Software Architectures . 21 2.2.1 Components and Connectors . 22 2.2.2 Software Connector Roles . 28 2.2.3 Software Interconnection Models . 29 2.2.4 Composing Basic Connectors . 30 2.3 Synthesizing Software Architectures . 31 2.4 Ontologies in Software Architecture . 31 3 Bounded Combinatory Logic 33 3.1 Combinatory Logic . 33 3.2 Intersection Types . 35 3.2.1 Types . 36 3.2.2 Subtyping . 36 3.2.3 Paths . 38 3.2.4 Substitutions . 39 i ii CONTENTS 3.3 Bounded Combinatory Logic . 39 3.3.1 Type Assignment . 40 3.3.2 Relativized Inhabitation Problem . 41 3.4 Alternating Turing Machines . 43 3.5 Deciding Relativized Inhabitation . 44 3.6 Combinatory Logic Synthesis . 46 3.7 Related Work on Synthesis . 47 4 Optimization of CLS 51 4.1 Theoretical Algorithm . 52 4.1.1 Restricting Intersections in Substitutions . 52 4.1.2 Intersection Type Matching . 56 4.1.3 Matching Optimization . 59 4.1.4 Lookahead Optimization . 61 4.1.5 Experimental Evaluation . 66 4.2 Algorithmic Optimization . 71 4.2.1 Execution Graph . 72 4.2.2 Term Level Optimization . 77 4.2.3 Elimination of Redundant Calculations . 80 4.2.4 Parallel Computation . 87 4.3 A Distributed Algorithm for BCL0(\; ≤) Inhabitation . 94 5 Combinatory Logic Synthesizer 105 5.1 Reconstructing Inhabitants . 105 5.2 Implementation . 106 5.3 (CL)S Input Specification . 110 5.4 (CL)S Output Specification . 112 5.5 Additional Applications and Extensions . 115 6 Synthesis of Software Architectures 119 6.1 Software Connectors . 119 6.2 Type-theoretic Model . 120 6.2.1 Component . 120 6.2.2 Connector . 121 6.2.3 Building Blocks . 122 6.2.4 C&C Type Environment . 125 6.2.5 Taxonomy . 126 6.3 Combinatory Logic Connector Synthesis . 134 6.3.1 Synthesis of Connector . 134 6.3.2 Generation of a Connector . 135 6.3.3 Combinatory Logic Connector Synthesis Method . 136 CONTENTS iii 6.3.4 Example for Combinatory Logic Connector Synthesis . 136 6.3.5 Synthesis of Behavior . 138 6.3.6 Designing C&C Type Repositories and Templates . 139 6.4 Related Work . 143 7 ArchiType 147 7.1 UML2 Extension . 148 7.2 User Interface . 149 7.3 Synthesizing Connectors in UML2 . 150 7.4 Code Generation . 152 7.5 ArchiType Composition Language . 154 7.6 Staged Composition Synthesis . 159 7.6.1 Implementation Type Correctness . 161 7.7 Implementation . 162 7.8 Related Work . 164 8 Applications and Experiments 165 8.1 Secure Connectors . 166 8.1.1 Setup . 166 8.1.2 Execution of the Experiment . 166 8.1.3 Results . 167 8.1.4 Analysis and Discussion . 169 8.2 Detailed Broker Pattern Example . 170 8.2.1 Setup . 170 8.2.2 Execution . 173 8.2.3 Results, Analysis, and Discussion . 173 8.3 Enterprise Resource Planning Scenario . 174 8.3.1 Setup . 174 8.3.2 Execution . 175 8.3.3 Results . 179 8.4 e-Commerce Scenario . 179 8.4.1 Setup . 180 8.4.2 Execution . 180 8.4.3 Results . 188 8.4.4 Analysis and Discussion . 188 8.5 Collective Analysis and Discussion . 189 8.5.1 Expressiveness . 189 8.5.2 Applicability . 190 8.5.3 Adaptability . 190 8.5.4 Costs and Effort . 191 8.5.5 Usability . 192 iv CONTENTS 8.5.6 Limitations . 193 9 Conclusion 197 A Selected implementation details 199 A.1 Grammar of (CL)S's input language . 199 A.2 Example in the Listing in ArchiType CL . 201 A.3 Example Template in T4 . 202 A.4 Algorithm Listings . 205 A.4.1 Inhabitation Algorithm (data-centric part) . 205 B Experiments 207 B.1 Compiler . 207 B.1.1 Compiler Flags . 207 B.2 Benchmark Problems . 207 B.3 Configuration of the Test Systems . 209 B.3.1 Test System I - Desktop PC . 209 B.3.2 Test System II - Compute Server . 209 Acronyms 211 List of Figures 215 List of Tables 219 List of Algorithms 221 Bibliography 223 Index 241 Chapter 1 Introduction Software systems tend to be large and complex. These factors must be managed in the design and development of such systems. Except for product lines, software architectures are unique products. Design and development take the form of a project and the development process is repeated for every software system that is constructed. Over the years, software engineers designed and developed software appli- cations and -systems with increasing complexity. Different techniques have been developed to handle growing complexity of systems. A very powerful tool is the abstraction of a system's building blocks. The very low-level abstraction of functions in procedural programming was replaced by objects in object-oriented programming. From there, objects have been abstracted to distributed programming and after that to component-based programming. The idea of component-based programming is to divide software applications and -systems into reusable components. The advantage of reusable compo- nents is that the number of newly created components for a new application can be reduced by reusing existing components. That means that components only have to be developed for missing functionality that is not covered by existing components. The idea of component marketplaces emerged where components are traded. Furthermore, topically coherent components have been bundled into libraries or repositories in order to increase revenue for producers of such repositories and also to increase additional benefit for users of component repositories. In order to develop a component-based software application or -system suitable components have to be retrieved from a suitable component repository and composed or assembled in a way such that the composite application fulfills the functional and non-functional requirements demanded bythe end-user. 1 2 CHAPTER 1. INTRODUCTION As it turned out, it was not that easy to compose components in a goal- directed fashion. Components are typically documented in textual form. The sheer quantity of components that have to be used to compose the intended software application made such an approach intricate and error-prone. From this problem, the idea emerged to automate composition by synthesizing a composition plan describing which components have to be composed with other components to reach a specific synthesis goal. Component-oriented synthesis is the goal-directed construction of a composite software system composed by components residing in a component repository.
Load more

Recommended publications
  • First Class Overloading Via Insersection Type Parameters⋆
    First Class Overloading via Insersection Type Parameters? Elton Cardoso2, Carlos Camar~ao1, and Lucilia Figueiredo2 1 Universidade Federal de Minas Gerais, [email protected] 2 Universidade Federal de Ouro Preto [email protected], [email protected] Abstract The Hindley-Milner type system imposes the restriction that function parameters must have monomorphic types. Lifting this restric- tion and providing system F “first class" polymorphism is clearly desir- able, but comes with the difficulty that inference of types for system F is undecidable. More practical type systems incorporating types of higher- rank have recently been proposed, that rely on system F but require type annotations for the definition of functions with polymorphic type parameters. However, these type annotations inevitably disallow some possible uses of higher-rank functions. To avoid this problem and to pro- mote code reuse, we explore using intersection types for specifying the types of function parameters that are used polymorphically inside the function body, allowing a flexible use of such functions, on applications to both polymorphic or overloaded arguments. 1 Introduction The Hindley-Milner type system [9] (HM) has been successfuly used as the basis for type systems of modern functional programming languages, such as Haskell [23] and ML [20]. This is due to its remarkable properties that a compiler can in- fer the principal type for any language expression, without any help from the programmer, and the type inference algorithm [5] is relatively simple. This is achieved, however, by imposing some restrictions, a major one being that func- tion parameters must have monomorphic types. For example, the following definition is not allowed in the HM type system: foo g = (g [True,False], g ['a','b','c']) Since parameter g is used with distinct types in the function's body (being applied to both a list of booleans and a list of characters), its type cannot be monomorphic, and this definition of foo cannot thus be typed in HM.
    [Show full text]
  • Disjoint Polymorphism
    Disjoint Polymorphism João Alpuim, Bruno C. d. S. Oliveira, and Zhiyuan Shi The University of Hong Kong {alpuim,bruno,zyshi}@cs.hku.hk Abstract. The combination of intersection types, a merge operator and parametric polymorphism enables important applications for program- ming. However, such combination makes it hard to achieve the desirable property of a coherent semantics: all valid reductions for the same expres- sion should have the same value. Recent work proposed disjoint inter- sections types as a means to ensure coherence in a simply typed setting. However, the addition of parametric polymorphism was not studied. This paper presents Fi: a calculus with disjoint intersection types, a vari- ant of parametric polymorphism and a merge operator. Fi is both type- safe and coherent. The key difficulty in adding polymorphism is that, when a type variable occurs in an intersection type, it is not statically known whether the instantiated type will be disjoint to other compo- nents of the intersection. To address this problem we propose disjoint polymorphism: a constrained form of parametric polymorphism, which allows disjointness constraints for type variables. With disjoint polymor- phism the calculus remains very flexible in terms of programs that can be written, while retaining coherence. 1 Introduction Intersection types [20,43] are a popular language feature for modern languages, such as Microsoft’s TypeScript [4], Redhat’s Ceylon [1], Facebook’s Flow [3] and Scala [37]. In those languages a typical use of intersection types, which has been known for a long time [19], is to model the subtyping aspects of OO-style multiple inheritance.
    [Show full text]
  • Polymorphic Intersection Type Assignment for Rewrite Systems with Abstraction and -Rule Extended Abstract
    Polymorphic Intersection Type Assignment for Rewrite Systems with Abstraction and -rule Extended Abstract Steffen van Bakel , Franco Barbanera , and Maribel Fernandez´ Department of Computing, Imperial College, 180 Queen’s Gate, London SW7 2BZ. [email protected] Dipartimento di Matematica, Universita` degli Studi di Catania, Viale A. Doria 6, 95125 Catania, Italia. [email protected] LIENS (CNRS URA 8548), Ecole Normale Superieure,´ 45, rue d’Ulm, 75005 Paris, France. [email protected] Abstract. We define two type assignment systems for first-order rewriting ex- tended with application, -abstraction, and -reduction (TRS ). The types used in these systems are a combination of ( -free) intersection and polymorphic types. The first system is the general one, for which we prove a subject reduction theorem and show that all typeable terms are strongly normalisable. The second is a decidable subsystem of the first, by restricting types to Rank 2. For this sys- tem we define, using an extended notion of unification, a notion of principal type, and show that type assignment is decidable. Introduction The combination of -calculus (LC) and term rewriting systems (TRS) has attracted attention not only from the area of programming language design, but also from the rapidly evolving field of theorem provers. It is well-known by now that type disciplines provide an environment in which rewrite rules and -reduction can be combined with- out loss of their useful properties. This is supported by a number of results for a broad range of type systems [11, 12, 20, 7, 8, 5]. In this paper we study the combination of LC and TRS as a basis for the design of a programming language.
    [Show full text]
  • Rank 2 Type Systems and Recursive De Nitions
    Rank 2 typ e systems and recursive de nitions Technical Memorandum MIT/LCS/TM{531 Trevor Jim Lab oratory for Computer Science Massachusetts Institute of Technology August 1995; revised Novemb er 1995 Abstract We demonstrate an equivalence b etween the rank 2 fragments of the p olymorphic lamb da calculus System F and the intersection typ e dis- cipline: exactly the same terms are typable in each system. An imme- diate consequence is that typability in the rank 2 intersection system is DEXPTIME-complete. Weintro duce a rank 2 system combining intersections and p olymorphism, and prove that it typ es exactly the same terms as the other rank 2 systems. The combined system sug- gests a new rule for typing recursive de nitions. The result is a rank 2 typ e system with decidable typ e inference that can typ e some inter- esting examples of p olymorphic recursion. Finally,we discuss some applications of the typ e system in data representation optimizations suchasunboxing and overloading. Keywords: Rank 2 typ es, intersection typ es, p olymorphic recursion, boxing/unboxing, overloading. 1 Intro duction In the past decade, Milner's typ e inference algorithm for ML has b ecome phenomenally successful. As the basis of p opular programming languages like Standard ML and Haskell, Milner's algorithm is the preferred metho d of typ e inference among language implementors. And in the theoretical 545 Technology Square, Cambridge, MA 02139, [email protected]. Supp orted by NSF grants CCR{9113196 and CCR{9417382, and ONR Contract N00014{92{J{1310.
    [Show full text]
  • A Facet-Oriented Modelling
    A Facet-oriented modelling JUAN DE LARA, Universidad Autónoma de Madrid (Spain) ESTHER GUERRA, Universidad Autónoma de Madrid (Spain) JÖRG KIENZLE, McGill University (Canada) Models are the central assets in model-driven engineering (MDE), as they are actively used in all phases of software development. Models are built using metamodel-based languages, and so, objects in models are typed by a metamodel class. This typing is static, established at creation time, and cannot be changed later. Therefore, objects in MDE are closed and fixed with respect to the class they conform to, the fields they have, and the wellformedness constraints they must comply with. This hampers many MDE activities, like the reuse of model-related artefacts such as transformations, the opportunistic or dynamic combination of metamodels, or the dynamic reconfiguration of models. To alleviate this rigidity, we propose making model objects open so that they can acquire or drop so-called facets. These contribute with a type, fields and constraints to the objects holding them. Facets are defined by regular metamodels, hence being a lightweight extension of standard metamodelling. Facet metamodels may declare usage interfaces, as well as laws that govern the assignment of facets to objects (or classes). This paper describes our proposal, reporting on a theory, analysis techniques and an implementation. The benefits of the approach are validated on the basis of five case studies dealing with annotation models, transformation reuse, multi-view modelling, multi-level modelling and language product lines. Categories and Subject Descriptors: [Software and its engineering]: Model-driven software engineering; Domain specific languages; Design languages; Software design engineering Additional Key Words and Phrases: Metamodelling, Flexible Modelling, Role-Based Modelling, METADEPTH ACM Reference Format: Juan de Lara, Esther Guerra, Jörg Kienzle.
    [Show full text]
  • Approximations, Fibrations and Intersection Type Systems
    Approximations, Fibrations and Intersection Type Systems Damiano Mazza*, Luc Pellissier† & Pierre Vial‡ June 16, 2017 Introduction The discovery of linear logic [7] has introduced the notionof linearity in computer science and proof theory. A remarkable fact of linear logic lies in its approximation theorem, stating that an arbitrary proof (not necessarily linear, that is, using its premisses any number of times) can be approximated arbitrarily well by a linear proof. This notion of approximation has then been explored in different directions [4, 10,14]. Approximations are known to be related to relational models, which in turn are related to intersection types [2, 12, 13]. In this work, we investigate approximations in the “type-systems as functors” perspective pioneered by [11]. After recasting fundamental properties of type systems, such as subject reduction and expansion in this framework, we give an intersection type system framework for linear logic, whose derivations are simply-typed approximations. Any calculus that translates meaningfully to linear logic is then endowed by a intersection type system, computed by pulling back one of these intersection type systems for linear logic, and which inherit its properties. All standard intersection type systems (idempotent, such as in [6, 1] or not, such as in [3]) for call-by-name and call-by-value λ-calculus, characterizing weak, strong, and head normalization, fit in this picture, thus justifying the equation: Simply-typed approximations = intersection types derivations. We moreover obtain new type systems, by considering other translations and reductions. 1 What is a type system? The starting point of this research is the work of [11].
    [Show full text]
  • Deconfined Intersection Types in Java
    Deconfined Intersection Types in Java Dedicated to Maurizio Gabbrielli on the Occasion of His 60th Birthday Mariangiola Dezani-Ciancaglini Computer Science Department, University of Torino, Italy [email protected] Paola Giannini Department of Advanced Science and Technology, University of Eastern Piedmont, Alessandria, Italy [email protected] Betti Venneri Department of Statistics, Computer Science, Applications, University of Firenze, Italy betti.venneri@unifi.it Abstract We show how Java intersection types can be freed from their confinement in type casts, in such a way that the proposed Java extension is safe and fully compatible with the current language. To this aim, we exploit two calculi which formalise the simple Java core and the extended language, respectively. Namely, the second calculus extends the first one by allowing an intersection type to be used anywhere in place of a nominal type. We define a translation algorithm, compiling programs of the extended language into programs of the former calculus. The key point is the interaction between λ-expressions and intersection types, that adds safe expressiveness while being the crucial matter in the translation. We prove that the translation preserves typing and semantics. Thus, typed programs in the proposed extension are translated to typed Java programs. Moreover, semantics of translated programs coincides with the one of the source programs. 2012 ACM Subject Classification Theory of computation → Type structures; Theory of computation → Semantics and reasoning Keywords and phrases Intersection Types, Featherweight Java, Lambda Expressions Digital Object Identifier 10.4230/OASIcs.Gabbrielli.2020.3 Acknowledgements We are very pleased to dedicate this work to Maurizio, whose notable contri- butions to the theory of programming languages are well known and appreciated by the scientific community.
    [Show full text]
  • Declared Type Vs Object Type
    Declared Type Vs Object Type andEnforceable patronising and Silvio keeperless fimbriate Sax her laths evangelizations so essentially apotheosise that Jameson matrimonially rebroadcasts or hischants skatings. filthily, Flaggy is Lyle irrigationCytherean? treble Homomorphic shudderingly. Judas delaminating apishly and contingently, she demagnetized her Interface type attributes to type declared vs object They are building blocks for declaring types. Multiple constructors can be defined in a class. This use of patterns encourages consistency and reduces complexity for servers and clients. Object classes facilitate rapid development because they lessen the semantic gap between the code and the users. None along with checking that it has the right type. This answer has been undeleted. Useful in special relativity. Generic methods are methods that introduce their own type parameters. The package is not complete and contains no explicit imports. In short, link to only your code and be specific about what you want feedback on. Embedded reports whether the variable is an embedded field. Type for the results of type inference. Functions belong to the object type. Examples of instances of this type. Press J to jump to the feed. These are usually field types and names that will be associated with state variables at program run time; these state variables either belong to the class or specific instances of the class. The rational is similar to the justification for allowing multiple superclasses, that the Internet is so dynamic and flexible that dynamic changes to the hierarchy are required to manage this volatility. What is the output of the following program? Error: You must enter a valid Integer without commas.
    [Show full text]
  • Typing the Numeric Tower
    Typing the Numeric Tower Vincent St-Amour1, Sam Tobin-Hochstadt1, Matthew Flatt2, and Matthias Felleisen1 1 Northeastern University {stamourv,samth,matthias}@ccs.neu.edu 2 University of Utah [email protected] Abstract. In the past, the creators of numerical programs had to choose between simple expression of mathematical formulas and static type checking. While the Lisp family and its dynamically typed relatives support the straightforward ex- pression via a rich numeric tower, existing statically typed languages force pro- grammers to pollute textbook formulas with explicit coercions or unwieldy nota- tion. In this paper, we demonstrate how the type system of Typed Racket accom- modates both a textbook programming style and expressive static checking. The type system provides a hierarchy of numeric types that can be freely mixed as well as precise specifications of sign, representation, and range information—all while supporting generic operations. In addition, the type system provides infor- mation to the compiler so that it can perform standard numeric optimizations. 1 Designing the Numeric Tower From the classic two-line factorial program to financial applications to scientific com- putation to graphics software, programs rely on numbers and numeric computations. Because of this spectrum of numeric applications, programmers wish to use a wide vari- ety of numbers: the inductively defined natural numbers, fixed-width integers, floating- point numbers, complex numbers, etc. Supporting this variety demands careful attention to the design of programming languages that manipulate numbers. Most languages have taken one of two approaches to numbers. Many untyped lan- guages, drawing on the tradition of Lisp and Smalltalk, provide a hierarchy of numbers whose various levels can be freely used together, known as the numeric tower.
    [Show full text]
  • Object-Oriented Dynamic GIS for Transportation Planning Reginald
    Object-Oriented Dynamic GIS for Transportation Planning Reginald G Gotledge Working Paper UCTC No 3 37 The University of Califorma Trans portatlon Center Umve~-slty of Cahforma Berkeley, CA94720 The University of California Transportation Center The Umverslty of Cahforma Center actaVltles Researchers TransportaUon Center (UCTC) at other umversmes w~thmthe as one of ten regional umts regmn also have opportunmes mandated by Congress and to collaborate wxth UCfaculty established m FaII 1988 to on selected studms support research, educatmn, and trramng m surface trans- UCTC’seducauonal and portatmn The UC Center research programs are focused serves federal RegmnIX and on strategm planning for ~s supported by matching improwng metropol~tan grants from the U S Depart- accessibility, wath emphas~s ment of Transportatmn the on the specml condmons in Calfforma Department of Region IX Partacular attentmn Transportation (Caltrans), and as directed to strategms for the Umversaty using transportatmn as an instrument of economic Based on the Berkeley development, whale also ac- Campus, UCTCdraws upon commodating to the regmn s existing capabdatms and persastent expansmn and resources of the Insututes of whale mmntammgand enhanc- Transportatmn Studies at ing the quahty of hfe there Berkeley, Davas, Irvme, and Los Angeles, the Insutute of The Center dxstnbutes reports Urban and Regional Develop- on ~ts research m working ment at Berkeley, and several papers, monographs, and in academac departments at the reprints of pubhshedarticles Berkeley, Davas,
    [Show full text]
  • Disjoint Intersection Types: Theory and Practice
    Disjoint Intersection Types: Theory and Practice by Xuan Bi (毕旋) A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at The University of Hong Kong December 2018 Abstract of thesis entitled “Disjoint Intersection Types: Theory and Practice” Submitted by Xuan Bi for the degree of Doctor of Philosophy at The University of Hong Kong in December 2018 Programs are hard to write. It was so 50 years ago at the time of the so-called software crisis; it still remains so nowadays. Over the years, we have learned—the hard way—that software should be constructed in a modular way, i.e., as a network of smaller and loosely connected modules. To facilitate writing modular code, researchers and software practitioners have developed new methodologies; new programming paradigms; stronger type systems; as well as better tooling support. Still, this is not enough to cope with today’s needs. Several reasons have been raised for the lack of satisfactory solutions, but one that is constantly pointed out is the inadequacy of existing programming languages for the construction of modular software. This thesis investigates disjoint intersection types, a variant of intersection types. Disjoint intersections types have great potential to serve as a foundation for powerful, flexible and yet type-safe and easy to reason OO languages, suitable for writing modular software. On the theoretical side, this thesis shows how to significantly increase the expressiveness of disjoint intersection types by adding support for nested composition, along with parametric polymor- phism. Nested composition extends inheritance to work on a whole family of classes, en- abling high degrees of modularity and code reuse.
    [Show full text]
  • The Grace Programming Language Draft Specification Version 0.5. 2025" (2015)
    Portland State University PDXScholar Computer Science Faculty Publications and Presentations Computer Science 2015 The Grace Programming Language Draft Specification ersionV 0.5. 2025 Andrew P. Black Portland State University, [email protected] Kim B. Bruce James Noble Follow this and additional works at: https://pdxscholar.library.pdx.edu/compsci_fac Part of the Programming Languages and Compilers Commons Let us know how access to this document benefits ou.y Citation Details Black, Andrew P.; Bruce, Kim B.; and Noble, James, "The Grace Programming Language Draft Specification Version 0.5. 2025" (2015). Computer Science Faculty Publications and Presentations. 140. https://pdxscholar.library.pdx.edu/compsci_fac/140 This Working Paper is brought to you for free and open access. It has been accepted for inclusion in Computer Science Faculty Publications and Presentations by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. The Grace Programming Language Draft Specification Version 0.5.2025 Andrew P. Black Kim B. Bruce James Noble April 2, 2015 1 Introduction This is a specification of the Grace Programming Language. This specifica- tion is notably incomplete, and everything is subject to change. In particular, this version does not address: • James IWE MUST COMMIT TO CLASS SYNTAX!J • the library, especially collections and collection literals • static type system (although we’ve made a start) • module system James Ishould write up from DYLA paperJ • dialects • the abstract top-level method, as a marker for abstract methods, • identifier resolution rule. • metadata (Java’s @annotations, C] attributes, final, abstract etc) James Ishould add this tooJ Kim INeed to add syntax, but not necessarily details of which attributes are in language (yet)J • immutable data and pure methods.
    [Show full text]