An Overview of the Scala Programming Language
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Lackwit: a Program Understanding Tool Based on Type Inference
Lackwit: A Program Understanding Tool Based on Type Inference Robert O’Callahan Daniel Jackson School of Computer Science School of Computer Science Carnegie Mellon University Carnegie Mellon University 5000 Forbes Avenue 5000 Forbes Avenue Pittsburgh, PA 15213 USA Pittsburgh, PA 15213 USA +1 412 268 5728 +1 412 268 5143 [email protected] [email protected] same, there is an abstraction violation. Less obviously, the ABSTRACT value of a variable is never used if the program places no By determining, statically, where the structure of a constraints on its representation. Furthermore, program requires sets of variables to share a common communication induces representation constraints: a representation, we can identify abstract data types, detect necessary condition for a value defined at one site to be abstraction violations, find unused variables, functions, used at another is that the two values must have the same and fields of data structures, detect simple errors in representation1. operations on abstract datatypes, and locate sites of possible references to a value. We compute representation By extending the notion of representation we can encode sharing with type inference, using types to encode other kinds of useful information. We shall see, for representations. The method is efficient, fully automatic, example, how a refinement of the treatment of pointers and smoothly integrates pointer aliasing and higher-order allows reads and writes to be distinguished, and storage functions. We show how we used a prototype tool to leaks to be exposed. answer a user’s questions about a 17,000 line program We show how to generate and solve representation written in C. -
Armadillo C++ Library
Armadillo: a template-based C++ library for linear algebra Conrad Sanderson and Ryan Curtin Abstract The C++ language is often used for implementing functionality that is performance and/or resource sensitive. While the standard C++ library provides many useful algorithms (such as sorting), in its current form it does not provide direct handling of linear algebra (matrix maths). Armadillo is an open source linear algebra library for the C++ language, aiming towards a good balance between speed and ease of use. Its high-level application programming interface (function syntax) is deliberately similar to the widely used Matlab and Octave languages [4], so that mathematical operations can be expressed in a familiar and natural manner. The library is useful for algorithm development directly in C++, or relatively quick conversion of research code into production environments. Armadillo provides efficient objects for vectors, matrices and cubes (third order tensors), as well as over 200 associated functions for manipulating data stored in the objects. Integer, floating point and complex numbers are supported, as well as dense and sparse storage formats. Various matrix factorisations are provided through integration with LAPACK [3], or one of its high performance drop-in replacements such as Intel MKL [6] or OpenBLAS [9]. It is also possible to use Armadillo in conjunction with NVBLAS to obtain GPU-accelerated matrix multiplication [7]. Armadillo is used as a base for other open source projects, such as MLPACK, a C++ library for machine learning and pattern recognition [2], and RcppArmadillo, a bridge between the R language and C++ in order to speed up computations [5]. -
Top 15 ERP Software Vendors – 2010
Top 15 ERP Software Vendors – 2010 Profiles of the Leading ERP Vendors Find the best ERP system for your company. For more information visit Business-Software.com/ERP. About ERP Software Enterprise resource planning (ERP) is not a new concept. It was introduced more than 40 years ago, when the first ERP system was created to improve inventory control and management at manufacturing firms. Throughout the 70’s and 80’s, as the number of companies deploying ERP increased, its scope expanded quite a bit to include various production and materials management functions, although it was designed primarily for use in manufacturing plants. In the 1990’s, vendors came to realize that other types of business could benefit from ERP, and that in order for a business to achieve true organizational efficiency, it needed to link all its internal business processes in a cohesive and coordinated way. As a result, ERP was transformed into a broad-reaching environment that encompassed all activities across the back office of a company. What is ERP? An ERP system combines methodologies with software and hardware components to integrate numerous critical back-office functions across a company. Made up of a series of “modules”, or applications that are seamlessly linked together through a common database, an ERP system enables various departments or operating units such as Accounting and Finance, Human Resources, Production, and Fulfillment and Distribution to coordinate activities, share information, and collaborate. Key Benefits for Your Company ERP systems are designed to enhance all aspects of key operations across a company’s entire back-office – from planning through execution, management, and control. -
Scala−−, a Type Inferred Language Project Report
Scala−−, a type inferred language Project Report Da Liu [email protected] Contents 1 Background 2 2 Introduction 2 3 Type Inference 2 4 Language Prototype Features 3 5 Project Design 4 6 Implementation 4 6.1 Benchmarkingresults . 4 7 Discussion 9 7.1 About scalac ....................... 9 8 Lessons learned 10 9 Language Specifications 10 9.1 Introdution ......................... 10 9.2 Lexicalsyntax........................ 10 9.2.1 Identifiers ...................... 10 9.2.2 Keywords ...................... 10 9.2.3 Literals ....................... 11 9.2.4 Punctions ...................... 12 9.2.5 Commentsandwhitespace. 12 9.2.6 Operations ..................... 12 9.3 Syntax............................ 12 9.3.1 Programstructure . 12 9.3.2 Expressions ..................... 14 9.3.3 Statements ..................... 14 9.3.4 Blocksandcontrolflow . 14 9.4 Scopingrules ........................ 16 9.5 Standardlibraryandcollections. 16 9.5.1 println,mapandfilter . 16 9.5.2 Array ........................ 16 9.5.3 List ......................... 17 9.6 Codeexample........................ 17 9.6.1 HelloWorld..................... 17 9.6.2 QuickSort...................... 17 1 of 34 10 Reference 18 10.1Typeinference ....................... 18 10.2 Scalaprogramminglanguage . 18 10.3 Scala programming language development . 18 10.4 CompileScalatoLLVM . 18 10.5Benchmarking. .. .. .. .. .. .. .. .. .. .. 18 11 Source code listing 19 1 Background Scala is becoming drawing attentions in daily production among var- ious industries. Being as a general purpose programming language, it is influenced by many ancestors including, Erlang, Haskell, Java, Lisp, OCaml, Scheme, and Smalltalk. Scala has many attractive features, such as cross-platform taking advantage of JVM; as well as with higher level abstraction agnostic to the developer providing immutability with persistent data structures, pattern matching, type inference, higher or- der functions, lazy evaluation and many other functional programming features. -
Higher-Order Functions 15-150: Principles of Functional Programming – Lecture 13
Higher-order Functions 15-150: Principles of Functional Programming { Lecture 13 Giselle Reis By now you might feel like you have a pretty good idea of what is going on in functional program- ming, but in reality we have used only a fragment of the language. In this lecture we see what more we can do and what gives the name functional to this paradigm. Let's take a step back and look at ML's typing system: we have basic types (such as int, string, etc.), tuples of types (t*t' ) and functions of a type to a type (t ->t' ). In a grammar style (where α is a basic type): τ ::= α j τ ∗ τ j τ ! τ What types allowed by this grammar have we not used so far? Well, we could, for instance, have a function below a tuple. Or even a function within a function, couldn't we? The following are completely valid types: int*(int -> int) int ->(int -> int) (int -> int) -> int The first one is a pair in which the first element is an integer and the second one is a function from integers to integers. The second one is a function from integers to functions (which have type int -> int). The third type is a function from functions to integers. The two last types are examples of higher-order functions1, i.e., a function which: • receives a function as a parameter; or • returns a function. Functions can be used like any other value. They are first-class citizens. Maybe this seems strange at first, but I am sure you have used higher-order functions before without noticing it. -
Avoiding the Top 10 Software Security Design Flaws
AVOIDING THE TOP 10 SOFTWARE SECURITY DESIGN FLAWS Iván Arce, Kathleen Clark-Fisher, Neil Daswani, Jim DelGrosso, Danny Dhillon, Christoph Kern, Tadayoshi Kohno, Carl Landwehr, Gary McGraw, Brook Schoenfield, Margo Seltzer, Diomidis Spinellis, Izar Tarandach, and Jacob West CONTENTS Introduction ..................................................................................................................................................... 5 Mission Statement ..........................................................................................................................................6 Preamble ........................................................................................................................................................... 7 Earn or Give, but Never Assume, Trust ...................................................................................................9 Use an Authentication Mechanism that Cannot be Bypassed or Tampered With .................... 11 Authorize after You Authenticate ...........................................................................................................13 Strictly Separate Data and Control Instructions, and Never Process Control Instructions Received from Untrusted Sources ........................................................................................................... 14 Define an Approach that Ensures all Data are Explicitly Validated .............................................16 Use Cryptography Correctly .................................................................................................................... -
First Steps in Scala Typing Static Typing Dynamic and Static Typing
CS206 First steps in Scala CS206 Typing Like Python, Scala has an interactive mode, where you can try What is the biggest difference between Python and Scala? out things or just compute something interactively. Python is dynamically typed, Scala is statically typed. Welcome to Scala version 2.8.1.final. In Python and in Scala, every piece of data is an object. Every scala> println("Hello World") object has a type. The type of an object determines what you Hello World can do with the object. Dynamic typing means that a variable can contain objects of scala> println("This is fun") different types: This is fun # This is Python The + means different things. To write a Scala script, create a file with name, say, test.scala, def test(a, b): and run it by saying scala test.scala. print a + b In the first homework you will see how to compile large test(3, 15) programs (so that they start faster). test("Hello", "World") CS206 Static typing CS206 Dynamic and static typing Static typing means that every variable has a known type. Dynamic typing: Flexible, concise (no need to write down types all the time), useful for quickly writing short programs. If you use the wrong type of object in an expression, the compiler will immediately tell you (so you get a compilation Static typing: Type errors found during compilation. More error instead of a runtime error). robust and trustworthy code. Compiler can generate more efficient code since the actual operation is known during scala> varm : Int = 17 compilation. m: Int = 17 Java, C, C++, and Scala are all statically typed languages. -
HECO-UNIX-Top Cladding Screw Into the Timber
HECO-UNIX -top Cladding Screw THE UNIQUE CLADDING SCREW WITH CONTRACTION EFFECT APPLICATION EXAMPLES Façade construction Secure and reliable façade fixing Louvred façades 1 2 3 The variable pitch of the HECO-UNIX full The smaller thread pitch means that the Gap free axial fixing of the timber board thread takes hold boards are clamped firmly together via the HECO-UNIX full thread PRODUCT CHARACTERISTICS The HECO-UNIX-top Cladding Screw into the timber. The façade is secured axially via with contraction effect the thread, which increases the pull-out strength. HECO-UNIX-top full thread This results in fewer fastening points and an Timber façades are becoming increasingly popular ultimately more economical façade construction. Contraction effect thanks to the full in both new builds and renovations. This applica - Thanks to the full thread, the sole function of thread with variable thread pitch tion places high demands on fastenings. The the head is to fit the screw drive. As such, the Axial fixing of component façade must be securely fixed to the sub-structure HECO-UNIX-top façade screw has a small and the fixings should be invisible or attractive raised head, which allows simple, concealed Reduced spreading effect thanks to to look at. In addition, the structure must be installation preventing any water penetration the HECO-TOPIX ® tip permanently sound if it is constantly exposed to through the screw. The screws are made of the weather. The HECO-UNIX-top façade screw stainless steel A2, which safely eliminates the Raised countersunk head is the perfect solution to all of these requirements. -
Typescript Language Specification
TypeScript Language Specification Version 1.8 January, 2016 Microsoft is making this Specification available under the Open Web Foundation Final Specification Agreement Version 1.0 ("OWF 1.0") as of October 1, 2012. The OWF 1.0 is available at http://www.openwebfoundation.org/legal/the-owf-1-0-agreements/owfa-1-0. TypeScript is a trademark of Microsoft Corporation. Table of Contents 1 Introduction ................................................................................................................................................................................... 1 1.1 Ambient Declarations ..................................................................................................................................................... 3 1.2 Function Types .................................................................................................................................................................. 3 1.3 Object Types ...................................................................................................................................................................... 4 1.4 Structural Subtyping ....................................................................................................................................................... 6 1.5 Contextual Typing ............................................................................................................................................................ 7 1.6 Classes ................................................................................................................................................................................. -
Scala Tutorial
Scala Tutorial SCALA TUTORIAL Simply Easy Learning by tutorialspoint.com tutorialspoint.com i ABOUT THE TUTORIAL Scala Tutorial Scala is a modern multi-paradigm programming language designed to express common programming patterns in a concise, elegant, and type-safe way. Scala has been created by Martin Odersky and he released the first version in 2003. Scala smoothly integrates features of object-oriented and functional languages. This tutorial gives a great understanding on Scala. Audience This tutorial has been prepared for the beginners to help them understand programming Language Scala in simple and easy steps. After completing this tutorial, you will find yourself at a moderate level of expertise in using Scala from where you can take yourself to next levels. Prerequisites Scala Programming is based on Java, so if you are aware of Java syntax, then it's pretty easy to learn Scala. Further if you do not have expertise in Java but you know any other programming language like C, C++ or Python, then it will also help in grasping Scala concepts very quickly. Copyright & Disclaimer Notice All the content and graphics on this tutorial are the property of tutorialspoint.com. Any content from tutorialspoint.com or this tutorial may not be redistributed or reproduced in any way, shape, or form without the written permission of tutorialspoint.com. Failure to do so is a violation of copyright laws. This tutorial may contain inaccuracies or errors and tutorialspoint provides no guarantee regarding the accuracy of the site or its contents including this tutorial. If you discover that the tutorialspoint.com site or this tutorial content contains some errors, please contact us at [email protected] TUTORIALS POINT Simply Easy Learning Table of Content Scala Tutorial .......................................................................... -
Dell EMC Powerstore CLI Guide
Dell EMC PowerStore CLI Guide May 2020 Rev. A01 Notes, cautions, and warnings NOTE: A NOTE indicates important information that helps you make better use of your product. CAUTION: A CAUTION indicates either potential damage to hardware or loss of data and tells you how to avoid the problem. WARNING: A WARNING indicates a potential for property damage, personal injury, or death. © 2020 Dell Inc. or its subsidiaries. All rights reserved. Dell, EMC, and other trademarks are trademarks of Dell Inc. or its subsidiaries. Other trademarks may be trademarks of their respective owners. Contents Additional Resources.......................................................................................................................4 Chapter 1: Introduction................................................................................................................... 5 Overview.................................................................................................................................................................................5 Use PowerStore CLI in scripts.......................................................................................................................................5 Set up the PowerStore CLI client........................................................................................................................................5 Install the PowerStore CLI client.................................................................................................................................. -
The Scala Experience Safe Programming Can Be Fun!
The Scala Programming Language Mooly Sagiv Slides taken from Martin Odersky (EPFL) Donna Malayeri (CMU) Hila Peleg (Technion) Modern Functional Programming • Higher order • Modules • Pattern matching • Statically typed with type inference • Two viable alternatives • Haskel • Pure lazy evaluation and higher order programming leads to Concise programming • Support for domain specific languages • I/O Monads • Type classes • ML/Ocaml/F# • Eager call by value evaluation • Encapsulated side-effects via references • [Object orientation] Then Why aren’t FP adapted? • Education • Lack of OO support • Subtyping increases the complexity of type inference • Programmers seeks control on the exact implementation • Imperative programming is natural in certain situations Why Scala? (Coming from OCaml) • Runs on the JVM/.NET • Can use any Java code in Scala • Combines functional and imperative programming in a smooth way • Effective libraries • Inheritance • General modularity mechanisms The Java Programming Language • Designed by Sun 1991-95 • Statically typed and type safe • Clean and Powerful libraries • Clean references and arrays • Object Oriented with single inheritance • Interfaces with multiple inheritance • Portable with JVM • Effective JIT compilers • Support for concurrency • Useful for Internet Java Critique • Downcasting reduces the effectiveness of static type checking • Many of the interesting errors caught at runtime • Still better than C, C++ • Huge code blowouts • Hard to define domain specific knowledge • A lot of boilerplate code •