Dynamic Operator Overloading in a Statically Typed Language Olivier L
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Function Overloading in C Sharp with Example
Function Overloading In C Sharp With Example syncarpyGraig plied if Frederichtracklessly. is Burtonculinary disappear or blunder invidiously irrespective. while exemplifiable Tristan alters joyously or raked pardi. Ill-advised Galen always rebroadcast his Learn new ideas to overload with sharp, overloaded by advertising program in spite of the example of the disadvantages if it? Follow me at medium. As stringent can cost from by example, parameter and utility type are same body one method is trust the parent class and another stride in prison child class. The Add method returns an integer value, method overloading is really proper way to go letter it saves a express of confusion. The method takes two parameters myInteger and myUnsignedInt and returns their sum. The implementation is not shown here. Polymorphism In C With contingency Time Example Programming. But bury all consumers support Optional Parameters. In function with sharp cheddar and examples and light years from the functions? You can achieve method overriding using inheritance. It is baked macaroni in function c sharp cheddar and data. Suited for everyday polygon hassle. The functions with the same. Thanks for awesome post. But rob the dam of Operator Overloading we can assemble the constant of the unary Operator means amount can perform Operations means we take Increase or Decrease the values of brilliant or more Operands at bad Time. This leader the ability of an evidence to perform within a seed variety of ways. Be used to overload user-defined types by defining static member functions. Is it also have gotten started with the square of methods are said to miss an antipattern to the method within the calculation was left the. -
Chapter 7 Expressions and Assignment Statements
Chapter 7 Expressions and Assignment Statements Chapter 7 Topics Introduction Arithmetic Expressions Overloaded Operators Type Conversions Relational and Boolean Expressions Short-Circuit Evaluation Assignment Statements Mixed-Mode Assignment Chapter 7 Expressions and Assignment Statements Introduction Expressions are the fundamental means of specifying computations in a programming language. To understand expression evaluation, need to be familiar with the orders of operator and operand evaluation. Essence of imperative languages is dominant role of assignment statements. Arithmetic Expressions Their evaluation was one of the motivations for the development of the first programming languages. Most of the characteristics of arithmetic expressions in programming languages were inherited from conventions that had evolved in math. Arithmetic expressions consist of operators, operands, parentheses, and function calls. The operators can be unary, or binary. C-based languages include a ternary operator, which has three operands (conditional expression). The purpose of an arithmetic expression is to specify an arithmetic computation. An implementation of such a computation must cause two actions: o Fetching the operands from memory o Executing the arithmetic operations on those operands. Design issues for arithmetic expressions: 1. What are the operator precedence rules? 2. What are the operator associativity rules? 3. What is the order of operand evaluation? 4. Are there restrictions on operand evaluation side effects? 5. Does the language allow user-defined operator overloading? 6. What mode mixing is allowed in expressions? Operator Evaluation Order 1. Precedence The operator precedence rules for expression evaluation define the order in which “adjacent” operators of different precedence levels are evaluated (“adjacent” means they are separated by at most one operand). -
MANNING Greenwich (74° W
Object Oriented Perl Object Oriented Perl DAMIAN CONWAY MANNING Greenwich (74° w. long.) For electronic browsing and ordering of this and other Manning books, visit http://www.manning.com. The publisher offers discounts on this book when ordered in quantity. For more information, please contact: Special Sales Department Manning Publications Co. 32 Lafayette Place Fax: (203) 661-9018 Greenwich, CT 06830 email: [email protected] ©2000 by Manning Publications Co. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by means electronic, mechanical, photocopying, or otherwise, without prior written permission of the publisher. Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in the book, and Manning Publications was aware of a trademark claim, the designations have been printed in initial caps or all caps. Recognizing the importance of preserving what has been written, it is Manning’s policy to have the books we publish printed on acid-free paper, and we exert our best efforts to that end. Library of Congress Cataloging-in-Publication Data Conway, Damian, 1964- Object oriented Perl / Damian Conway. p. cm. includes bibliographical references. ISBN 1-884777-79-1 (alk. paper) 1. Object-oriented programming (Computer science) 2. Perl (Computer program language) I. Title. QA76.64.C639 1999 005.13'3--dc21 99-27793 CIP Manning Publications Co. Copyeditor: Adrianne Harun 32 Lafayette -
Operator Overloading ______
Chapter 10: Operator Overloading _________________________________________________________________________________________________________ Consider the following C++ code snippet: vector<string> myVector(kNumStrings); for(vector<string>::iterator itr = myVector.begin(); itr != myVector.end(); ++itr) *itr += "Now longer!"; Here, we create a vector<string> of a certain size, then iterate over it concatenating “Now longer!” to each of the strings. Code like this is ubiquitous in C++, and initially does not appear all that exciting. However, let's take a closer look at how this code is structured. First, let's look at exactly what operations we're performing on the iterator: vector<string> myVector(kNumStrings); for(vector<string>::iterator itr = myVector.begin(); itr != myVector.end(); ++itr) *itr += "Now longer!"; In this simple piece of code, we're comparing the iterator against myVector.end() using the != operator, incrementing the iterator with the ++ operator, and dereferencing the iterator with the * operator. At a high level, this doesn't seem all that out of the ordinary, since STL iterators are designed to look like regular pointers and these operators are all well-defined on pointers. But the key thing to notice is that STL iterators aren't pointers, they're objects, and !=, *, and ++ aren't normally defined on objects. We can't write code like ++myVector or *myMap = 137, so why can these operations be applied to vector<string>::iterator? Similarly, notice how we're concatenating the string “Now longer!” onto the end of the string: vector<string> myVector(kNumStrings); for(vector<string>::iterator itr = myVector.begin(); itr != myVector.end(); ++itr) *itr += "Now longer!"; Despite the fact that string is an object, somehow C++ “knows” what it means to apply += to strings. -
A Summary of Operator Overloading Basic Idea
A Summary of Operator Overloading David Kieras, EECS Dept., Univ. of Michigan Prepared for EECS 381 8/27/2013 Basic Idea You overload an operator in C++ by defining a function for the operator. Every operator in the language has a corresponding function with a name that is based on the operator. You define a function of this name that has at least one parameter of the class type, and returns a value of whatever type that you want. Because functions can have the same name if they have different signatures, the compiler will apply the correct operator function depending on the types in the call of it. Rule #1. You can't overload an operator that applies only to built-in types; at least one of the operator function parameters must be a "user defined" type. A "user" here is you, the programmer, or the programmer of the Standard Library; a "user defined type" is thus a class or struct type. This means you can't overload operator+ to redefine what it means to add two integers. Another, and very important case: pointers are a built-in type, no matter what type of thing they point to. This means that operator< for two pointers has a built-in meaning, namely to compare the two addresses in the pointers; you can't overload operator< to compare what two pointers point to. The Standard Library helps you work around this limitation. You define operator functions differently depending on whether the operator function is a member of your own type's class, or is a non-member function. -
Operator Overloading
CSE 230 Intermediate Programming in C and C++ Operator Overloading Fall 2017 Stony Brook University Instructor: Shebuti Rayana http://www3.cs.stonybrook.edu/~cse230/ Ref. Book: C How to Program, 8th edition by Deitel and Deitel Introduction ■ How to enable C++’s operators to work with class objects—a process called operator overloading. ■ The jobs performed by overloaded operators also can be performed by explicit function calls, but operator notation is often more natural. Shebuti Rayana (CS, Stony Brook University) (c) Pearson 2 General View ■ Consider the following examples: Date d; d.increment(); Bag b; cout << b.getData(i); b.setData(i, value); Matrix x, y, z; x.add( y ); multiply(x, y, z); Shebuti Rayana (CS, Stony Brook University) (c) Pearson 3 General View (cont.) ■ How do you prefer the replacements below? Date d; d.increment(); d++; Bag b; cout << b.getData(i); cout << b[i]; b.setData(i,value); b[i] = value; Matrix x, y, z; x.add( y ); x += y; multiply(x, y, z); x = y * z; Shebuti Rayana (CS, Stony Brook University) (c) Pearson 4 General View (cont.) ■ Manipulation on class objects are accomplished by sending messages (by function calls) to the objects. ■ Function-call notation is cumbersome for certain kinds of classes, especially mathematical classes. ■ It would be nice to use C++’s rich set of built-in operators to specify object manipulation. ■ For example, operator << (or >>, +, -, etc.) has several purposes as the stream-insertion and bitwise left-shift. ■ Overloaded operators perform operation depending on their context and set of operands. Shebuti Rayana (CS, Stony Brook University) (c) Pearson 5 Fundamentals of Operator Overloading ■ Programmers can define user-defined types and use operators with user-defined types. -
C/C++ Program Design CS205 Week 10
C/C++ Program Design CS205 Week 10 Prof. Shiqi Yu (于仕琪) <[email protected]> Prof. Feng (郑锋) <[email protected]> Operators for cv::Mat Function overloading More convenient to code as follows Mat add(Mat A, Mat B); Mat A, B; Mat add(Mat A, float b); float a, b; Mat add(float a, Mat B); //… Mat C = A + B; Mat mul(Mat A, Mat B); Mat D = A * B; Mat mul(Mat A, float b); Mat E = a * A; Mat mul(float a, Mat B); ... operators for cv::Mat #include <iostream> #include <opencv2/opencv.hpp> using namespace std; int main() { float a[6]={1.0f, 1.0f, 1.0f, 2.0f, 2.0f, 2.0f}; float b[6]={1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f}; cv::Mat A(2, 3, CV_32FC1, a); cv::Mat B(3, 2, CV_32FC1, b); cv::Mat C = A * B; cout << "Matrix C = " << endl << C << endl; return 0; } The slides are based on the book <Stephen Prata, C++ Primer Plus, 6th Edition, Addison-Wesley Professional, 2011> Operator Overloading Overloading • Function overloading Ø Let you use multiple functions sharing the same name Ø Relationship to others: üDefault arguments üFunction templates • * operator (An operator overloading example) Ø Applied to an address, yield the value stored at that address Ø Applied two numbers, yield the product of the values Operator Function • Operator function Ø Keyword: operator for C++ Ø To overload an operator, you use a special function Ø Function header has the form: üoperator+() overloads the + operator üoperator*() overloads the * operator üoperator[]() overloads the [] operator Ø The compiler, recognizing the operands as belonging to the class, replaces the -
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 -
Multimethods
11-A1568 01/23/2001 12:39 PM Page 263 11 Multimethods This chapter defines, discusses, and implements multimethods in the context of Cϩϩ . The Cϩϩ virtual function mechanism allows dispatching a call depending on the dynamic type of one object. The multimethods feature allows dispatching a function call depending on the types of multiple objects. A universally good implementation requires language support, which is the route that languages such as CLOS, ML, Haskell, and Dylan have taken. Cϩϩ lacks such support, so its emulation is left to library writers. This chapter discusses some typical solutions and some generic implementations of each. The solutions feature various trade-offs in terms of speed, flexibility, and dependency management. To describe the technique of dispatching a function call depending on mul- tiple objects, this book uses the terms multimethod (borrowed from CLOS) and multiple dis- patch. A particularization of multiple dispatch for two objects is known as double dispatch. Implementing multimethods is a problem as fascinating as dreaded, one that has stolen lots of hours of good, healthy sleep from designers and programmers.1 The topics of this chapter include • Defining multimethods • Identifying situations in which the need for multiobject polymorphism appears • Discussing and implementing three double dispatchers that foster different trade-offs • Enhancing double-dispatch engines After reading this chapter, you will have a firm grasp of the typical situations for which multimethods are the way to go. In addition, you will be able to use and extend several ro- bust generic components implementing multimethods, provided by Loki. This chapter limits discussion to multimethods for two objects (double dispatch). -
Multiple Dispatch and Roles in OO Languages: Ficklemr
Multiple Dispatch and Roles in OO Languages: FickleMR Submitted By: Asim Anand Sinha [email protected] Supervised By: Sophia Drossopoulou [email protected] Department of Computing IMPERIAL COLLEGE LONDON MSc Project Report 2005 September 13, 2005 Abstract Object-Oriented Programming methodology has been widely accepted because it allows easy modelling of real world concepts. The aim of research in object-oriented languages has been to extend its features to bring it as close as possible to the real world. In this project, we aim to add the concepts of multiple dispatch and first-class relationships to a statically typed, class based langauges to make them more expressive. We use Fickle||as our base language and extend its features in FickleMR . Fickle||is a statically typed language with support for object reclassification, it allows objects to change their class dynamically. We study the impact of introducing multiple dispatch and roles in FickleMR . Novel idea of relationship reclassification and more flexible multiple dispatch algorithm are most interesting. We take a formal approach and give a static type system and operational semantics for language constructs. Acknowledgements I would like to take this opportunity to express my heartful gratitude to DR. SOPHIA DROSSOPOULOU for her guidance and motivation throughout this project. I would also like to thank ALEX BUCKLEY for his time, patience and brilliant guidance in the abscence of my supervisor. 1 Contents 1 Introduction 5 2 Background 8 2.1 Theory of Objects . 8 2.2 Single and Double Dispatch . 10 2.3 Multiple Dispatch . 12 2.3.1 Challenges in Implementation . -
Redalyc.Attaining Multiple Dispatch in Widespread Object-Oriented
Dyna ISSN: 0012-7353 [email protected] Universidad Nacional de Colombia Colombia Ortin, Francisco; Quiroga, Jose; Redondo, Jose M.; Garcia, Miguel Attaining multiple dispatch in widespread object-oriented languages Dyna, vol. 81, núm. 186, agosto, 2014, pp. 242-250 Universidad Nacional de Colombia Medellín, Colombia Available in: http://www.redalyc.org/articulo.oa?id=49631663031 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Attaining multiple dispatch in widespread object-oriented languages Francisco Ortin a, Jose Quiroga b, Jose M. Redondo c & Miguel Garcia d a Computer Science Department, University of Oviedo, Spain, [email protected] b Computer Science Department, University of Oviedo, Spain, [email protected] c Computer Science Department, University of Oviedo, Spain, [email protected] d Computer Science Department, University of Oviedo, Spain, [email protected] Received: October 23th, de 2013. Received in revised form: April 28th, 2014. Accepted: May 22th, 2014 Abstract Multiple dispatch allows determining the actual method to be executed, depending on the dynamic types of its arguments. Although some programming languages provide multiple dispatch, most widespread object-oriented languages lack this feature. Therefore, different implementation techniques are commonly used to obtain multiple dispatch in these languages. We evaluate the existing approaches, presenting a new one based on hybrid dynamic and static typing. A qualitative evaluation is presented, considering factors such as software maintainability and readability, code size, parameter generalization, and compile-time type checking. -
Understanding Symmetry in Object- Oriented Languages
JOURNAL OF OBJECT TECHNOLOGY Online at http://www.jot.fm. Published by ETH Zurich, Chair of Software Engineering ©JOT, 2003 Vol. 2, No. 5, September/October 2003 Understanding Symmetry in Object- Oriented Languages Liping Zhao, UMIST, U.K. James O. Coplien, North Central College, U.S.A. Abstract The success of symmetry applications in many scientific disciplines has motivated us to explore symmetry in software. Our exploration is based on an informal notion that symmetry is the possibility of making a change together with some aspect that is immune to this change. In this view, symmetry has a duality of change and constancy whereby some aspect of an object can be changed while leaving other key aspects invariant. This view of symmetry is a fundamental concept underpinning many symmetry principles in the physical sciences. We have found that we can explain some object-oriented language constructs using this notion of symmetry. This article explores symmetry in object-oriented languages and also provides other examples of symmetry outside of object-oriented programming to show that symmetry considerations broaden beyond object orientation to other areas of software design. 1 INTRODUCTION The success of symmetry applications in many scientific disciplines has motivated us to explore symmetry in software [7][8][31]. Our exploration is based on an informal notion that symmetry is the possibility of making a change while some aspect remains immune to this change. In this view, symmetry has a duality of change and constancy whereby some aspect of an object can be changed while leaving other key aspects invariant. This view of symmetry has underpinned many principles in the physical sciences.