DOCSLIB.ORG

A Really Good Idea

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Really Good Idea We should not underestimate the suc- cess. David Taylor wrote in “Software [R]evolution: A Roundtable” (Computer, A Really May 1999, p. 50) that “by the year 2000 no one would talk about objects any more Component and Object Technology because the technology would be so thor- oughly absorbed into the mainstream that Good Idea no one would think to mention it.” His time frame may be premature by a few Bertrand Meyer, ISE years but absorption is definitely the trend. All major developments in the software world integrate OO aspects or at least claim to do so. Almost all recent pro- gramming languages are OO in some s this is the final installment of ways; even good old Fortran, in its latest the Component and Object version, has some timid support for data Technology column, I will try abstraction. This may be what Al Davis’s to come back to the source, consulting clients really mean: We know A object-oriented development, all about objects, don’t bother us with this. and reflect on its contribution and future. But it’s a sign of success, not rejection. Wise people have at various times pre- dicted or even announced the end of IT’S THE ONLY GAME IN TOWN objects. As early as 1989 (see Scott Whatever reservations anyone may Guthery, “Are the Emperor’s New have about some or another aspect of Clothes Object-Oriented?” Dr. Dobb’s Don’t blame OO current object technology, it is still true Journal, Dec. 1989, p. 80), articles were programming in general that, as Grady Booch noted a few years appearing on the “object winter” theme, for the limitations of ago, we don’t really know any better; patterned after the “AI winter” reported those who don’t know when it comes to building complex, evo- to have followed the initial excitement how to apply the lutionary, mission-critical systems, OO over artificial intelligence. The theme has principles. solutions are our best bet. Nothing else gained new vigor in the past few months. has come to challenge them. In Software Development (July 1999, Nothing, not even component-based p. 33), a review by Alan Zeichik of development. As has been clear in this Clemens Szyperski’s Component Soft- word ‘object.’ Now, none do, and I find column, with all my enthusiasm for com- ware book states: “Whether we like it or that clients are much happier when they ponent-based development, leading in not, in most situations object-oriented don’t.” He follows this with a final blow: particular to the column’s broadening of programming has not succeeded in fos- “I think ‘object’ has now gone the way scope last year (from “Object Tech- tering code reuse, except in the most lim- of ‘structured.’” nology” to “Component and Object ited way.” The comparison with structured pro- Technology”) and to the special section Recently, IEEE Software has been the gramming is appropriate: In the case of on CBD (co-edited with Christine place of choice for death notices, with structured programming, too, a set of Mingins, in last July’s issue of Com- such pronouncements by former editor- simple but profound conceptual princi- puter), I find absurd the claim that (in in-chief Al Davis as “We are all now wit- ples enjoyed partial success, a passage of Alan Zeichik’s phrase) “objects are tired, nessing the fall of the Object era” some of the ideas into the fabric of daily components are wired.” Components, to (“Predictions and Farewell,” July/Aug. software development to the point of misquote Clausewitz, are just the pursuit 1998, pp. 6-9). In his final interview (“A becoming so obvious that many practi- of objects through other means. Com- Golden Thread in Software’s Tapestry,” tioners do not realize that the ideas were ponents assume object technology, they Nov./Dec. 1998, pp. 18-21) he says, once new and controversial; in addition use object technology, and they promote “When I started consulting ten years ago, to this success, these conceptual princi- object technology. all my customers wanted to hear the ples suffered a form of degradation, com- Every one of the currently prominent ing in part from the transfer of the name CBD approaches is directly rooted in Editor: Bertrand Meyer, Interactive “structured” to denote mere graphical objects, be it CORBA, Enterprise Java- Software Engineering, ISE Bldg., 2nd Fl., conventions for describing system struc- Beans, or COM with its direct reliance 270 Storke Rd., Goleta, CA 93117; voice tures, useful in themselves but a far cry on the Vtables of C++. (805) 685-6869; [email protected] from the intellectual discipline of the One can understand the buzz-of-the- original ideas. year phenomenon, if only as a way for 144 Computer consultants to renew their claims to exper- of object technology, and, more gener- anyone chosen 02 as a pivot?) will be the tise. We in the software field don’t have ally, many of the principles of modern opportunity for a mini-Y2K. preseason sales and postseason discounts, programming methodology. There is no excuse for such nonsense. so we need ever new ways to drum up It passes on to our successors the same business. There’s nothing wrong with that; THE NEXT 99 SOFTWARE DISASTERS calamity that our predecessors (in some let’s just not take it too seriously. Perhaps the most striking example of cases ourselves) inflicted on us. But they David Taylor, in the roundtable cited what we still have to learn is the success at least had the excuse that it was the first above, noted that “Even Object Magazine of the so-called windowing Y2K tech- time, that no one knew, and that we were changed its name to Component Software nique. I don’t have any actual statistics, all learning. This time there is no such to maintain its cutting edge.” That was but informal inquiries suggest it’s one of excuse; we should know better. quite amusing, since a couple of months the most commonly used “solutions” to after Taylor’s article Component Software LESSON NOT HEEDED? announced that it was merging with The Y2K mess as a whole is evidence Application Development, retaining the While many engineers that, for all the talk about objects having latter’s title. Does this mean that compo- and managers are familiar become mainstream, we still have a long nents are out and we are now back to with the basic goals of way to go, and not only regarding the applications? Probably not. A marketing object technology, only more advanced parts of object technology. strategy is not a technology trend. a minority has really In this department’s column about the understood the deeper topic (Christopher Creele, Bertrand TEACHING THOSE concepts and started to Meyer, and Philippe Stephan, “The Op- WHO ALREADY KNOW apply them thoroughly. portunity of a Millennium,” Computer, The “we know all about objects so Nov. 1997, pp. 137-138), we pointed out what else is new” attitude cited by Al that the millennium problem was the Davis is indeed widespread. In my expe- the Y2K issue. Windowing means that opportunity for a generalized opening-up rience it is largely unjustified. While you don’t touch files and databases using and cleaning-up of major software sys- many engineers and managers are famil- two-digit dates; you just choose a pivot tems. All signs indicate that this has hap- iar with the basic goals of object tech- date, say 1960, and hack the programs pened only in a minority of enlightened nology, only a minority has really so that whenever they use a 2-digit date companies. Others have simply patched understood the deeper concepts and code xy they do something like their code and are hoping for the best started to apply them thoroughly. This (including hoping that the patching can make life tough for object technol- if xy < 60 then process will not have introduced too ogy consultants and instructors: As every Understand this as the many new bugs). For all these companies, parent and educator knows, it is impos- date 20xy object technology is still in the future. sible to teach people something when else What object technology? This is where they think they already know it. Understand this as the we must again take a serious look at the I find that general intellectual sympa- date 19xy supposed arguments against object tech- thy with the principles of information end nology. (You can find a set of links in the hiding, data abstraction, taxonomy, “pros and cons” section of the Cetus OO reuse, systematic software construc- There can be no universal pivot date, so links at http://www.cetus-links.org/oo_ tion—an attitude found fairly universally “60” is just an example. An airline’s fre- infos.html#oo_general_info_general_ today—is not a good predictor of quent flyer system doesn’t need to go articles.) Although the criticism is offi- whether the person will actually apply back any earlier than 1970, but the air- cially directed at object technology, what these principles in software development. line’s pension program may have to deal it really addresses in many cases is C++. To anyone who has the opportunity of with people born in 1910. In an early article about object technol- peeking at the way companies large and Now this is really clever. First we make ogy, Bjarne Stroustrup mocked the pseu- small routinely write software these days, the programs even more complicated dosyllogism “Ada is good; Ada is OO; the myth that object technology is now than before, with all kinds of spurious therefore OO is good.” What we have passé sounds absurd.
Load more

Recommended publications
  • Declarative Immutability in Java
    International Journal of Computer and Systems Engineering Volume 1 Issue 1 Article 4 July 2020 Declarative Immutability in Java John Crowley Boston College, University of Pennsylvania, [email protected] Follow this and additional works at: https://digitalcommons.fairfield.edu/ijcase Recommended Citation Crowley, John (2020) "Declarative Immutability in Java," International Journal of Computer and Systems Engineering: Vol. 1 : Iss. 1 , Article 4. Available at: https://digitalcommons.fairfield.edu/ijcase/vol1/iss1/4 This item has been accepted for inclusion in DigitalCommons@Fairfield by an authorized administrator of DigitalCommons@Fairfield. It is brought to you by DigitalCommons@Fairfield with permission from the rights- holder(s) and is protected by copyright and/or related rights. You are free to use this item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses, you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/or on the work itself. For more information, please contact [email protected]. Declarative Immutability in Java Online at https://digitalcommons.fairfield.edu/ijcase/ Published by Fairfield University, DigitalCommons@Fairfield © 2020 Vol. 1, No. 1, 2020 Declarative Immutability in Java by John D. Crowley ABSTRACT A pervasive mechanism is proposed to declare that variables and object instances are mutable or immutable, and whether methods mutate instances. These declarations are integral to the type structure of the language and allow the developer to declare, and the reader (and compiler) to determine, if a variable or instance is immutable (even if other instances of the Class are mutable) or that an instance is immutable throughout the application (a Pure instance).
    [Show full text]
  • Scala for the Impatient Second Edition This Page Intentionally Left Blank Scala for the Impatient Second Edition
    Scala for the Impatient Second Edition This page intentionally left blank Scala for the Impatient Second Edition Cay S. Horstmann Boston • Columbus • Indianapolis • New York • San Francisco • Amsterdam • Cape Town Dubai • London • Madrid • Milan • Munich • Paris • Montreal • Toronto • Delhi • Mexico City São Paulo • Sydney • Hong Kong • Seoul • Singapore • Taipei • Tokyo 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 publisher was aware of a trademark claim, the designations have been printed with initial capital letters or in all capitals. The author and publisher have taken care in the preparation of this book, but make no expressed or implied warranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of the use of the information or programs contained herein. For information about buying this title in bulk quantities, or for special sales opportunities (which may include electronic versions; custom cover designs; and content particular to your business, training goals, marketing focus, or branding interests), please contact our corporate sales department at [email protected] or (800) 382–3419. For government sales inquiries, please contact [email protected]. For questions about sales outside the United States, please contact [email protected]. Visit us on the Web: informit.com/aw Library of Congress Control Number: 2016954825 Copyright © 2017 Pearson Education, Inc. All rights reserved. Printed in the United States of America. This publication is protected by copyright, and permission must be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise.
    [Show full text]
  • The Pragmatic Programmer Your Journey to Mastery
    Extracted from: The Pragmatic Programmer your journey to mastery 20th Anniversary Edition Boston • Columbus • New York • San Francisco • Amsterdam • Cape Town Dubai • London • Madrid • Milan • Munich • Paris • Montreal • Toronto • Delhi • Mexico City São Paulo • Sydney • Hong Kong • Seoul • Singapore • Taipei • Tokyo The Pragmatic Programmer your journey to mastery 20th Anniversary Edition Dave Thomas Andy Hunt Boston • Columbus • New York • San Francisco • Amsterdam • Cape Town Dubai • London • Madrid • Milan • Munich • Paris • Montreal • Toronto • Delhi • Mexico City São Paulo • Sydney • Hong Kong • Seoul • Singapore • Taipei • Tokyo 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 publisher was aware of a trademark claim, the designations have been printed with initial capital letters or in all capitals. "The Pragmatic Programmer" and the linking g device are trademarks of The Pragmatic Programmers, LLC. The authors and publisher have taken care in the preparation of this book, but make no expressed or implied warranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of the use of the information or programs contained herein. For information about buying this title in bulk quantities, or for special sales opportunities (which may include electronic versions; custom cover designs; and content particular to your business, training goals, marketing focus, or branding interests), please contact our corporate sales department at [email protected] or (800) 382-3419. For government sales inquiries, please contact [email protected]. For questions about sales outside the U.S., please contact [email protected].
    [Show full text]
  • Study on Eiffel
    Study on Eiffel Jie Yao Anurag Katiyar May 11, 2008 Abstract This report gives an introduction to Eiffel, an object oriented language. The objective of the report is to draw the attention of the reader to the salient features of Eiffel. The report explains some of these features in brief along with language syntax. The report includes some code snippets that were written in the process of learning Eiffel. Some of the more detailed tutorials, books and papers on Eiffel can be found at www.eiffel.com 1 Contents 1 Introduction 3 2 Eiffel Constructs and Grammar 3 2.1 ”Hello World” . 3 2.2 Data Types . 3 2.3 Classes . 3 2.4 Libraries . 4 2.5 Features . 4 2.6 Class relations and hierarchy . 4 2.7 Inheritance . 4 2.8 Genericity . 5 2.9 Object Creation . 5 2.10 Exceptions . 6 2.11 Agents and Iteration . 6 2.12 Tuples . 6 2.13 Typing . 6 2.14 Scope . 7 2.15 Memory Management . 7 2.16 External software . 7 3 Fundamental Properties 7 3.1 ”Has” Properties . 8 3.2 ”Has no” Properties . 9 4 Design principles in Eiffel 10 4.1 Design by Contract . 10 4.2 Command Query Separation . 11 4.3 Uniform Access Principle . 11 4.4 Single Choice Principle . 11 5 Compilation Process in Eiffel 11 6 Exception Handling in the compiler 12 7 Garbage Collection for Eiffel 12 7.1 Garbage Collector Structure . 12 7.2 Garbage Collector in Action . 13 8 Eiffel’s approach to typing 13 8.1 Multiple inheritance .
    [Show full text]
  • Software Quality / Modularity
    Software quality EXTERNAL AND INTERNAL FACTORS External quality factors are properties such as speed or ease of use, whose presence or absence in a software product may be detected by its users. Other qualities applicable to a software product, such as being modular, or readable, are internal factors, perceptible only to computer professionals who have access to the actual software text. In the end, only external factors matter, but the key to achieving these external factors is in the internal ones: for the users to enjoy the visible qualities, the designers and implementers must have applied internal techniques that will ensure the hidden qualities. EXTERNAL FACTORS Correctness: The ability of software products to perform their tasks, as defined by their specification. Correctness is the prime quality. If a system does not do what it is supposed to do, everything else about it — whether it is fast, has a nice user interface¼ — matters little. But this is easier said than done. Even the first step to correctness is already difficult: we must be able to specify the system requirements in a precise form, by itself quite a challenging task. Robustness: The ability of software systems to react appropriately to abnormal conditions. Robustness complements correctness. Correctness addresses the behavior of a system in cases covered by its specification; robustness characterizes what happens outside of that specification. There will always be cases that the specification does not explicitly address. The role of the robustness requirement is to make sure that if such cases do arise, the system does not cause catastrophic events; it should produce appropriate error messages, terminate its execution cleanly, or enter a so-called “graceful degradation” mode.
    [Show full text]
  • Polymorphic Identifiers: Uniform Resource Access in Objective-Smalltalk
    Polymorphic Identifiers: Uniform Resource Access in Objective-Smalltalk Marcel Weiher Robert Hirschfeld Hasso Plattner Institute, University of Potsdam Hasso Plattner Institute, University of Potsdam [email protected] [email protected] Abstract compose these identifiers, use them on the LHS and RHS and In object-oriented programming, polymorphic dispatch of opera- partially use them for indirect access. Computational abstraction tions decouples clients from specific providers of services and al- is handled separately. lows implementations to be modified or substituted without affect- Object-oriented programming languages such as Smalltalk, ing clients. Java and Objective-C mostly maintain the distinction between The Uniform Access Principle (UAP) tries to extend these qual- computational and storage abstraction, with polymorphism and ities to resource access by demanding that access to state be indis- most other abstraction mechanisms only applying to computational tinguishable from access to operations. Despite language features abstraction. Access to storage, when not mediated via a method, supporting the UAP, the overall goal of substitutability has not been defeats encapsulation and makes code brittle against changes or achieved for either alternative resources such as keyed storage, files subclassing, which is why convention moved toward having all or web pages, or for alternate access mechanisms: specific kinds of access to state (instance variables) mediated by methods. resources are bound to specific access mechanisms and vice versa. The Uniform Access Principle (UAP) [22] was coined by Meyer Changing storage or access patterns either requires changes to both to formalize this convention: access to state should be indistin- clients and service providers and trying to maintain the UAP im- guishable from computation.
    [Show full text]
  • Best Practices in Software Development: Principles of Good
    Best Practices in Software Development: Principles of Good Design Ansgar Fehnker Based on slides by: Arend Rensink, Christoph Bockisch, Mira Mezini, Lodewijk Bergmans What is Good Software? . External criteria . Correctness, robustness, extensibility, efficiency, ease of use ... Stakeholders: . end user, e.g., a travel agent using a flight reservation system . persons who purchase the software, e.g., an airline executive acquiring or commissioning flight reservation systems . Internal criteria . Modularity, readability, reusability, ... Stakeholders: . IT professionals with access to the source . Only external factors matter in the end . but the key to achieving them is in the internal ones Patterns of Software Development 2 External vs. Internal Criteria Patterns of Software Development 3 External Criteria: Correctness . What is correctness? . the ability of a software product to perform its task . as defined by its specification . Examples of (in-)correct systems? Application . Due to complexity, methods for ensuring correctness will usually be conditional or layered . each layer relying on lower ones Hardware Patterns of Software Development 4 External Criteria: Robustness . What is robustness? . the ability of software to react appropriately to abnormal conditions . Examples of (non-)robust systems? . Difference robustness/correctness? . Correctness addresses the behavior of a system in cases covered by its specification . Robustness characterizes what happens outside of that specification Patterns of Software Development 5 External Criteria: Efficiency . What is efficiency? . place as few demands as possible on hardware resources: . processor time, memory, bandwidth, power . Examples of (in-)efficient systems? . A software case of split personality . Mr. Microsecond: shows an exaggerated concern for micro- optimisation. “Premature optimization is the root of all evil” .
    [Show full text]
  • Object Oriented Programming Objects What's Interesting
    Object Oriented Programming Objects • An object consists of • Primary object-oriented language concepts − hidden or private part − dynamic lookup Hidden part ◊ instance variables / − encapsulation feature1 . data members − inheritance ◊ possibly, also some private feature2 . − subtyping functions • OO program − • Program organization public part − Creates a “root object” − Organize concepts into objects and relationships between them ◊ public operations, or member ◊ which may create other objects − Build program to be extensible functions, or methods, or ◊ which, in turn, may create other “messages” ◊ Both open and closed objects ... ◊ possibly, also some public − Objects • Comparison instance variables ◊ send messages to / invoke − Objects as closures? • In Eiffel terminology: methods on / apply features of other objects features L. Dillon, CSE 452, Fall 2008 1 L. Dillon, CSE 452, Fall 2008 2 What’s interesting about this? Why study Eiffel? • Universal encapsulation construct • Completely object-oriented approach from start to finish − Flight simulator • Design by contract (DBC) method − File system • Language mechanisms supporting OO and DBC − Database − Classes, objects, assertions, contracts, ... − − Window Single & multiple inheritance with ◊ redefinition − List ◊ undefinition − Integer ◊ renaming − Genericity: contrained & unconstrained • Metaphor usefully ambiguous − Uniform type system: safe covariance − sequential or concurrent computation − Agents (power of functional programming in OO) − “Once” mechanisms − distributed, synchronous
    [Show full text]
  • Eiffel and C++ Are Statically Typed, Class- Based Object-Oriented Languages
    EEiiffeffell aanndd CC++++ A comparison between two Object-Oriented languages Tom Van Cutsem CCllaasssseess aanndd OObbjjeecctsts Both Eiffel and C++ are statically typed, class- based object-oriented languages. Both regard class definitions as type definitions. Both make a clear distinction between classes and objects. Eiffel is a pure object-oriented language, C++ is impure (multi-paradigm). CCllaasssseess aanndd OObbjjeecctsts CC++++ State encapsulated in ‘data members’. Behaviour encapsulated in ‘memberfunctions’. Manual memory Management Four so called ‘special member functions’: the constructor, the destructor, the copy constructor and the assignment operator. CCllaasssseess aanndd OObbjjeecctsts EEiiffeffell Automatic Garbage Collection Eiffel classes consist of features: class HELLO create make feature make is -- Print a simple message. do io.put_string ("Hello World") io.put_new_line end end -- class HELLO CCllaasssseess aanndd OObbjjeecctsts EEiiffeffell Two viewpoints on features. From the viewpoint of the defining class, a feature is an attribute, a function or a procedure. From the viewpoint of the client class, a feature is a command or a query. Client Supplier Procedure Command Function Feature Query Attribute CCllaasssseess aanndd OObbjjeecctsts EEiiffeffell The client class does not see the difference between attribute access and a parameterless function call: the Uniform Access Principle myBalance := myAccount.balance implemented as an attribute class ACCOUNT feature balance: INTEGER end CCllaasssseess aanndd OObbjjeecctsts EEiiffeffell The client class does not see the difference between attribute access and a parameterless function call: the Uniform Access Principle myBalance := myAccount.balance implemented as a function class ACCOUNT feature -- an instance variable thebalance: INTEGER feature -- access the balance balance is do balance := thebalance end CCllaasssseess aanndd OObbjjeecctsts In C++, classes without ancestors become the root of a new hierarchy.
    [Show full text]
  • Applying Aspect-Oriented Software Development to Middleware Frameworks
    APPLYING ASPECT-ORIENTED SOFTWARE DEVELOPMENT TO MIDDLEWARE FRAMEWORKS TAL COHEN APPLYING ASPECT-ORIENTED SOFTWARE DEVELOPMENT TO MIDDLEWARE FRAMEWORKS RESEARCH THESIS IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY TAL COHEN SUBMITTED TO THE SENATE OF THE TECHNION — ISRAEL INSTITUTE OF TECHNOLOGY ADAR, 5767 HAIFA FEBRUARY 2007 THIS RESEARCH THESIS WAS DONE UNDER THE SUPERVISION OF DR. JOSEPH (YOSSI) GIL IN THE DEPARTMENT OF COMPUTER SCIENCE I would like to thank the many people who have directly or indirectly helped me during the long period of research. I thank my supervisor, Yossi Gil, who never ceased to amaze me; my friend and co-student Itay Maman, who greatly helped in large parts of this research; Prof. Shmuel Katz, who first introduced me to the world of aspect-oriented programming; Omer Barkol, who was a wonderful office-mate these last few years; Prof. Ron Pinter, who advised and encouraged; and lastly, Yardena Kolet, the final authority in the CS faculty. This work is dedicated to my family: to my parents, Rachel and Nahum; to my beloved wife Irit; and to my two wonderful children, Stav and Yuval: May you always have rea- sons for joy! THE GENEROUS FINANCIAL HELP OF THE TECHNION IS GRATEFULLY AC- KNOWLEDGED. Contents List of Figures v List of Tables ix Abstract 1 1 Introduction 3 1.1 Why Existing Solutions Are Broken . 6 1.1.1 Limitations of the Services-Based Solution . 6 1.1.2 Limitations of Existing AOP Solutions . 7 1.1.3 Marrying J2EE with AOP . 9 1.2 Contributions and Outline .
    [Show full text]
  • (Programming) Addison-Wesley
    I l@ve RuBoard Front Matter Table of Contents About the Author Pragmatic Programmer, The: From Journeyman to Master Andrew Hunt David Thomas Publisher: Addison Wesley First Edition October 13, 1999 ISBN: 0-201-61622-X, 352 pages Straight from the programming trenches, The Pragmatic Programmer cuts through the increasing specialization and technicalities of modern software development to examine the core process--taking a requirement and producing working, maintainable code that delights its users. It covers topics ranging from personal responsibility and career development to architectural techniques for keeping your code flexible and easy to adapt and reuse. Read this book, and you’ll learn how to: Fight software rot; Avoid the trap of duplicating knowledge; Write flexible, dynamic, and adaptable code; Avoid programming by coincidence; Bullet-proof your code with contracts, assertions, and exceptions; Capture real requirements; Test ruthlessly and effectively; Delight your users; Build teams of pragmatic programmers; and Make your developments more precise with automation. Written as a series of self-contained sections and filled with entertaining anecdotes, thoughtful examples, and interesting analogies, The Pragmatic Programmer illustrates the best practices and major pitfalls of many different aspects of software development. Whether you’re a new coder, an experienced programmer, or a manager responsible for software projects, use these lessons daily, and you’ll quickly see improvements in personal productivity, accuracy, and job satisfaction. You’ll learn skills and develop habits and attitudes that form the foundation for long-term success in your career. You’ll become a Pragmatic Programmer. I l@ve RuBoard I l@ve RuBoard Pragmatic Programmer, The: From Journeyman to Master Foreword Preface Who Should Read This Book? What Makes a Pragmatic Programmer? Individual Pragmatists, Large Teams It's a Continuous Process How the Book Is Organized What's in a Name? 1.
    [Show full text]
  • 3 Modularity
    3 Modularity From the goals of extendibility and reusability, two of the principal quality factors introduced in chapter 1, follows the need for flexible system architectures, made of autonomous software components. This is why chapter 1 also introduced the term modularity to cover the combination of these two quality factors. Modular programming was once taken to mean the construction of programs as assemblies of small pieces, usually subroutines. But such a technique cannot bring real extendibility and reusability benefits unless we have a better way of guaranteeing that the resulting pieces — the modules — are self-contained and organized in stable architectures. Any comprehensive definition of modularity must ensure these properties. A software construction method is modular, then, if it helps designers produce software systems made of autonomous elements connected by a coherent, simple structure. The purpose of this chapter is to refine this informal definition by exploring what precise properties such a method must possess to deserve the “modular” label. The focus will be on design methods, but the ideas also apply to earlier stages of system construction (analysis, specification) and must of course be maintained at the implementation and maintenance stages. As it turns out, a single definition of modularity would be insufficient; as with software quality, we must look at modularity from more than one viewpoint. This chapter introduces a set of complementary properties: five criteria, five rules and five principles of modularity which, taken collectively, cover the most important requirements on a modular design method. For the practicing software developer, the principles and the rules are just as important as the criteria.
    [Show full text]