Class Declaration in Perl
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Mixins and Traits
◦ ◦◦◦ TECHNISCHE UNIVERSITAT¨ MUNCHEN¨ ◦◦◦◦ ◦ ◦ ◦◦◦ ◦◦◦◦ ¨ ¨ ◦ ◦◦ FAKULTAT FUR INFORMATIK Programming Languages Mixins and Traits Dr. Michael Petter Winter 2016/17 What advanced techiques are there besides multiple implementation inheritance? Outline Design Problems Cons of Implementation Inheritance 1 Inheritance vs Aggregation 1 2 (De-)Composition Problems Lack of finegrained Control 2 Inappropriate Hierarchies Inheritance in Detail A Focus on Traits 1 A Model for single inheritance 1 2 Inheritance Calculus with Separation of Composition and Inheritance Expressions Modeling 2 3 Modeling Mixins Trait Calculus Mixins in Languages Traits in Languages 1 (Virtual) Extension Methods 1 Simulating Mixins 2 Squeak 2 Native Mixins Reusability ≡ Inheritance? Codesharing in Object Oriented Systems is often inheritance-centric. Inheritance itself comes in different flavours: I single inheritance I multiple inheritance All flavours of inheritance tackle problems of decomposition and composition The Adventure Game Door ShortDoor LockedDoor canPass(Person p) canOpen(Person p) ? ShortLockedDoor canOpen(Person p) canPass(Person p) The Adventure Game Door <interface>Doorlike canPass(Person p) canOpen(Person p) Short canPass(Person p) Locked canOpen(Person p) ShortLockedDoor ! Aggregation & S.-Inheritance Door must explicitely provide canOpen(Person p) chaining canPass(Person p) Doorlike must anticipate wrappers ) Multiple Inheritance X The Wrapper FileStream SocketStream read() read() write() write() ? SynchRW acquireLock() releaseLock() ! Inappropriate Hierarchies -
[PDF] Beginning Raku
Beginning Raku Arne Sommer Version 1.00, 22.12.2019 Table of Contents Introduction. 1 The Little Print . 1 Reading Tips . 2 Content . 3 1. About Raku. 5 1.1. Rakudo. 5 1.2. Running Raku in the browser . 6 1.3. REPL. 6 1.4. One Liners . 8 1.5. Running Programs . 9 1.6. Error messages . 9 1.7. use v6. 10 1.8. Documentation . 10 1.9. More Information. 13 1.10. Speed . 13 2. Variables, Operators, Values and Procedures. 15 2.1. Output with say and print . 15 2.2. Variables . 15 2.3. Comments. 17 2.4. Non-destructive operators . 18 2.5. Numerical Operators . 19 2.6. Operator Precedence . 20 2.7. Values . 22 2.8. Variable Names . 24 2.9. constant. 26 2.10. Sigilless variables . 26 2.11. True and False. 27 2.12. // . 29 3. The Type System. 31 3.1. Strong Typing . 31 3.2. ^mro (Method Resolution Order) . 33 3.3. Everything is an Object . 34 3.4. Special Values . 36 3.5. :D (Defined Adverb) . 38 3.6. Type Conversion . 39 3.7. Comparison Operators . 42 4. Control Flow . 47 4.1. Blocks. 47 4.2. Ranges (A Short Introduction). 47 4.3. loop . 48 4.4. for . 49 4.5. Infinite Loops. 53 4.6. while . 53 4.7. until . 54 4.8. repeat while . 55 4.9. repeat until. 55 4.10. Loop Summary . 56 4.11. if . .. -
Declaring Vars in Class Php
Declaring Vars In Class Php Is Tobe Esculapian or misformed after aluminous Neall plopping so magnanimously? Forrest corresponds prolixly? Forbidden Osmund sometimes pargets any lilliputian yell guardedly. How variable as int, php in using interpolation rather than configured one of people prefer to override whatever information useful whenever you call it leads to expose parts that We daily work with advertisers relevant to our readers. Acceptable in php programmers and retry saving again, declaration must be. Declaring a property but a class is an exact task use one table the keyword public protected or private followed by a normal variable declaration If. If you wrong there holding an IE bug with var a foo only declaring a global for file scope. Your class declaration format is declared protected field? You help also define methods in the class that allow tool to manipulate the values of object properties and perform operations on objects. PHP Class Properties Tutorials by Supun Kavinda. An amazon associate we declare the class in declarations as containers for our clients in the usages of a name given client exits and in? How clean and in declaring a class declaration scope in the vars of that are their parent selector. Using long array syntax array 1 2 3 for declaring arrays is generally. By declaring a class declaration, classes and see for? It turns out some interview situations, every time to magento source and other class names but you have a common occurrence, therefore considered a value. The var keyword in PHP is used to declare the property or variable of class which is primitive by default The var keyword is alike as out when declaring variables or root of a class Note The var keyword was deprecated from version 50. -
Learning Javascript Design Patterns
Learning JavaScript Design Patterns Addy Osmani Beijing • Cambridge • Farnham • Köln • Sebastopol • Tokyo Learning JavaScript Design Patterns by Addy Osmani Copyright © 2012 Addy Osmani. All rights reserved. Revision History for the : 2012-05-01 Early release revision 1 See http://oreilly.com/catalog/errata.csp?isbn=9781449331818 for release details. ISBN: 978-1-449-33181-8 1335906805 Table of Contents Preface ..................................................................... ix 1. Introduction ........................................................... 1 2. What is a Pattern? ...................................................... 3 We already use patterns everyday 4 3. 'Pattern'-ity Testing, Proto-Patterns & The Rule Of Three ...................... 7 4. The Structure Of A Design Pattern ......................................... 9 5. Writing Design Patterns ................................................. 11 6. Anti-Patterns ......................................................... 13 7. Categories Of Design Pattern ............................................ 15 Creational Design Patterns 15 Structural Design Patterns 16 Behavioral Design Patterns 16 8. Design Pattern Categorization ........................................... 17 A brief note on classes 17 9. JavaScript Design Patterns .............................................. 21 The Creational Pattern 22 The Constructor Pattern 23 Basic Constructors 23 Constructors With Prototypes 24 The Singleton Pattern 24 The Module Pattern 27 iii Modules 27 Object Literals 27 The Module Pattern -
Mixin-Based Programming in C++1
Mixin-Based Programming in C++1 Yannis Smaragdakis Don Batory College of Computing Department of Computer Sciences Georgia Institute of Technology The University of Texas at Austin Atlanta, GA 30332 Austin, Texas 78712 [email protected] [email protected] Abstract. Combinations of C++ features, like inheritance, templates, and class nesting, allow for the expression of powerful component patterns. In particular, research has demonstrated that, using C++ mixin classes, one can express lay- ered component-based designs concisely with efficient implementations. In this paper, we discuss pragmatic issues related to component-based programming using C++ mixins. We explain surprising interactions of C++ features and poli- cies that sometimes complicate mixin implementations, while other times enable additional functionality without extra effort. 1 Introduction Large software artifacts are arguably among the most complex products of human intellect. The complexity of software has led to implementation methodologies that divide a problem into manageable parts and compose the parts to form the final prod- uct. Several research efforts have argued that C++ templates (a powerful parameteriza- tion mechanism) can be used to perform this division elegantly. In particular, the work of VanHilst and Notkin [29][30][31] showed how one can implement collaboration-based (or role-based) designs using a certain templatized class pattern, known as a mixin class (or just mixin). Compared to other techniques (e.g., a straightforward use of application frameworks [17]) the VanHilst and Notkin method yields less redundancy and reusable components that reflect the structure of the design. At the same time, unnecessary dynamic binding can be eliminated, result- ing into more efficient implementations. -
EN-Google Hacks.Pdf
Table of Contents Credits Foreword Preface Chapter 1. Searching Google 1. Setting Preferences 2. Language Tools 3. Anatomy of a Search Result 4. Specialized Vocabularies: Slang and Terminology 5. Getting Around the 10 Word Limit 6. Word Order Matters 7. Repetition Matters 8. Mixing Syntaxes 9. Hacking Google URLs 10. Hacking Google Search Forms 11. Date-Range Searching 12. Understanding and Using Julian Dates 13. Using Full-Word Wildcards 14. inurl: Versus site: 15. Checking Spelling 16. Consulting the Dictionary 17. Consulting the Phonebook 18. Tracking Stocks 19. Google Interface for Translators 20. Searching Article Archives 21. Finding Directories of Information 22. Finding Technical Definitions 23. Finding Weblog Commentary 24. The Google Toolbar 25. The Mozilla Google Toolbar 26. The Quick Search Toolbar 27. GAPIS 28. Googling with Bookmarklets Chapter 2. Google Special Services and Collections 29. Google Directory 30. Google Groups 31. Google Images 32. Google News 33. Google Catalogs 34. Froogle 35. Google Labs Chapter 3. Third-Party Google Services 36. XooMLe: The Google API in Plain Old XML 37. Google by Email 38. Simplifying Google Groups URLs 39. What Does Google Think Of... 40. GooglePeople Chapter 4. Non-API Google Applications 41. Don't Try This at Home 42. Building a Custom Date-Range Search Form 43. Building Google Directory URLs 44. Scraping Google Results 45. Scraping Google AdWords 46. Scraping Google Groups 47. Scraping Google News 48. Scraping Google Catalogs 49. Scraping the Google Phonebook Chapter 5. Introducing the Google Web API 50. Programming the Google Web API with Perl 51. Looping Around the 10-Result Limit 52. -
Name Description
Perl version 5.10.0 documentation - perlnewmod NAME perlnewmod - preparing a new module for distribution DESCRIPTION This document gives you some suggestions about how to go about writingPerl modules, preparing them for distribution, and making them availablevia CPAN. One of the things that makes Perl really powerful is the fact that Perlhackers tend to want to share the solutions to problems they've faced,so you and I don't have to battle with the same problem again. The main way they do this is by abstracting the solution into a Perlmodule. If you don't know what one of these is, the rest of thisdocument isn't going to be much use to you. You're also missing out onan awful lot of useful code; consider having a look at perlmod, perlmodlib and perlmodinstall before coming back here. When you've found that there isn't a module available for what you'retrying to do, and you've had to write the code yourself, considerpackaging up the solution into a module and uploading it to CPAN so thatothers can benefit. Warning We're going to primarily concentrate on Perl-only modules here, ratherthan XS modules. XS modules serve a rather different purpose, andyou should consider different things before distributing them - thepopularity of the library you are gluing, the portability to otheroperating systems, and so on. However, the notes on preparing the Perlside of the module and packaging and distributing it will apply equallywell to an XS module as a pure-Perl one. What should I make into a module? You should make a module out of any code that you think is going to beuseful to others. -
Coleman-Coding-Freedom.Pdf
Coding Freedom !" Coding Freedom THE ETHICS AND AESTHETICS OF HACKING !" E. GABRIELLA COLEMAN PRINCETON UNIVERSITY PRESS PRINCETON AND OXFORD Copyright © 2013 by Princeton University Press Creative Commons Attribution- NonCommercial- NoDerivs CC BY- NC- ND Requests for permission to modify material from this work should be sent to Permissions, Princeton University Press Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540 In the United Kingdom: Princeton University Press, 6 Oxford Street, Woodstock, Oxfordshire OX20 1TW press.princeton.edu All Rights Reserved At the time of writing of this book, the references to Internet Web sites (URLs) were accurate. Neither the author nor Princeton University Press is responsible for URLs that may have expired or changed since the manuscript was prepared. Library of Congress Cataloging-in-Publication Data Coleman, E. Gabriella, 1973– Coding freedom : the ethics and aesthetics of hacking / E. Gabriella Coleman. p. cm. Includes bibliographical references and index. ISBN 978-0-691-14460-3 (hbk. : alk. paper)—ISBN 978-0-691-14461-0 (pbk. : alk. paper) 1. Computer hackers. 2. Computer programmers. 3. Computer programming—Moral and ethical aspects. 4. Computer programming—Social aspects. 5. Intellectual freedom. I. Title. HD8039.D37C65 2012 174’.90051--dc23 2012031422 British Library Cataloging- in- Publication Data is available This book has been composed in Sabon Printed on acid- free paper. ∞ Printed in the United States of America 1 3 5 7 9 10 8 6 4 2 This book is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE !" We must be free not because we claim freedom, but because we practice it. -
A Foundation for Trait-Based Metaprogramming
A foundation for trait-based metaprogramming John Reppy Aaron Turon University of Chicago {jhr, adrassi}@cs.uchicago.edu Abstract We present a calculus, based on the Fisher-Reppy polymorphic Scharli¨ et al. introduced traits as reusable units of behavior inde- trait calculus [FR03], with support for trait privacy, hiding and deep pendent of the inheritance hierarchy. Despite their relative simplic- renaming of trait methods, and a more granular trait typing. Our ity, traits offer a surprisingly rich calculus. Trait calculi typically in- calculus is more expressive (it provides new forms of conflict- clude operations for resolving conflicts when composing two traits. resolution) and more flexible (it allows after-the-fact renaming) In the existing work on traits, these operations (method exclusion than the previous work. Traits provide a useful mechanism for shar- and aliasing) are shallow, i.e., they have no effect on the body of the ing code between otherwise unrelated classes. By adding deep re- other methods in the trait. In this paper, we present a new trait sys- naming, our trait calculus supports sharing code between methods. tem, based on the Fisher-Reppy trait calculus, that adds deep oper- For example, the JAVA notion of synchronized methods can im- ations (method hiding and renaming) to support conflict resolution. plemented as a trait in our system and can be applied to multiple The proposed operations are deep in the sense that they preserve methods in the same class to produce synchronized versions. We any existing connections between the affected method and the other term this new use of traits trait-based metaprogramming. -
Programming Languages
◦ ◦◦◦ TECHNISCHE UNIVERSITAT¨ MUNCHEN¨ ◦◦◦◦ ◦ ◦ ◦◦◦ ◦◦◦◦ ¨ ¨ ◦ ◦◦ FAKULTAT FUR INFORMATIK Programming Languages Traits Dr. Axel Simon and Dr. Michael Petter Winter term 2012 Traits 1 / 30 “Is Multiple Inheritance the holy grail of reusability?“ Learning outcomes 1 Identify problems of composition and decomposition 2 Understand semantics of traits 3 Separate function provision, object generation and class relations 4 Traits and existing program languages Traits Introduction 2 / 30 Reusability ≡ Inheritance? Codesharing in Object Oriented Systems is usually inheritance-centric. Inheritance itself comes in different flavours: I single inheritance I multiple inheritance I mixin inheritance All flavours of inheritance tackle problems of decomposition and composition Traits Problems with Inheritance and Composability 3 / 30 Streams FileStream SynchRW SocketStream read() acquireLock() read() write() releaseLock() write() read() write() SynchedFileStream SynchedSocketStream ! Duplicated Wrappers Multiple Inheritance is not applicable as super-References are statically bound ( Alternative: Mixins) Traits Problems with Inheritance and Composability Decomposition Problems 4 / 30 Streams modified FileStream SynchRW SocketStream read() acquireLock() read() write() releaseLock() write() SynchedFileStream SynchedSocketStream read() read() write() write() ! Duplicated Features read/write Code is essentially identical but duplicated Traits Problems with Inheritance and Composability Decomposition Problems 5 / 30 Oh my god, streams! SynchRW acquireLock() releaseLock() -
COMS 3101 Programming Languages: Perl Lecture 5
COMS 3101 Programming Languages: Perl Lecture 5 Fall 2013 Instructor: Ilia Vovsha http://www.cs.columbia.edu/~vovsha/coms3101/perl Lecture Outline Packages & Modules Concepts: Subroutine references SbliSymbolic references Garbage collection Saving structures Objects and Classes Next: More OOP, CPAN 5.2 Remarks Pattern matching “cage” can be any character: • m// or // is equivalent to m{} • s/// is equivalent to s{} {} • // are just customary quote characters for pattern matching behavior. In fact you could choose your own character instead of {} (e.g. m ! !) • Convenient if lots of slhlashes in the pattern ref function: returns type of reference (a string) • $rtype = ref($href); # returns “HASH” • $rtype = ref($aref); # returns “ARRAY” • if ( ref($href) eq “HASH” ) { … } 5.3 Packages & Modules Why do we need them? Package or module, what is the difference? ‘use’ vs. ‘require’ Importing from another package Pragmatic modules (ppgragmas) 5.4 Packages (purpose) sub parse_text { # code from one file … $count = $count++; … } sub normalize { # code from another file $count++; … } # Use both functions: parse_text(); normalize(); print “$count\n”; # Which $count? What is its value? 5.5 Packages (definition) Balanced code: abstraction + reuse Every chkhunk of code has its own namespace. In PlPerl, a namespace is called a package Independent of files: • Multiple packages in one file • Single package spanning multiple files • Most common: one package per file Best approach: one package per file where file name is package name -
Name Introduction Quick Checklist
Perl version 5.10.0 documentation - perlmodstyle NAME perlmodstyle - Perl module style guide INTRODUCTION This document attempts to describe the Perl Community's "best practice"for writing Perl modules. It extends the recommendations found in perlstyle , which should be considered required readingbefore reading this document. While this document is intended to be useful to all module authors, it isparticularly aimed at authors who wish to publish their modules on CPAN. The focus is on elements of style which are visible to the users of a module, rather than those parts which are only seen by the module's developers. However, many of the guidelines presented in this documentcan be extrapolated and applied successfully to a module's internals. This document differs from perlnewmod in that it is a style guiderather than a tutorial on creating CPAN modules. It provides achecklist against which modules can be compared to determine whether they conform to best practice, without necessarily describing in detailhow to achieve this. All the advice contained in this document has been gleaned fromextensive conversations with experienced CPAN authors and users. Everypiece of advice given here is the result of previous mistakes. Thisinformation is here to help you avoid the same mistakes and the extrawork that would inevitably be required to fix them. The first section of this document provides an itemized checklist; subsequent sections provide a more detailed discussion of the items on the list. The final section, "Common Pitfalls", describes some of the most popular mistakes made by CPAN authors. QUICK CHECKLIST For more detail on each item in this checklist, see below.