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Whiley (programming Language)
Whiley is an experimental programming language that combines features from the functional and imperative programming paradigms, and supports formal specification through function preconditions, postconditions and loop invariants. The language uses flow-sensitive typing also termed ''flow typing''. The Whiley project began in 2009 in response to the "Verifying Compiler Grand Challenge" put forward by Tony Hoare in 2003. The first public release of Whiley was in June, 2010. Developed by David Pearce mainly, Whiley is an open source project with contributions from a small community. The system has been used for student research projects and in teaching undergraduate classes. It was supported from 2012–2014 by the Royal Society of New Zealand's Marsden Fund. The Whiley compiler generates code for the Java virtual machine (JVM) and can interoperate with Java and other JVM-based languages. Overview The goal of Whiley is to provide a realistic programming language where verifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imperative Programming
In computer science, imperative programming is a programming paradigm of software that uses Statement (computer science), statements that change a program's state (computer science), state. In much the same way that the imperative mood in natural languages expresses commands, an imperative program consists of command (computing), commands for the computer to perform. Imperative programming focuses on describing ''how'' a program operates step by step (with general order of the steps being determined in source code by the placement of statements one below the other), rather than on high-level descriptions of its expected results. The term is often used in contrast to declarative programming, which focuses on ''what'' the program should accomplish without specifying all the details of ''how'' the program should achieve the result. Procedural programming Procedural programming is a type of imperative programming in which the program is built from one or more procedures (also termed s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flow-sensitive Typing
In programming language theory, flow-sensitive typing (also called flow typing or occurrence typing) is a type system where the type of an expression depends on its position in the control flow. In statically typed languages, a type of an expression is determined by the types of the sub-expressions that compose it. However, in flow-sensitive typing, an expression's type may be updated to a more specific type if it follows an operation that validates its type. Validating operations can include type predicates, imperative updates, and control flow. Examples Ceylon See the following example in Ceylon which illustrates the concept: // Object? means the variable "name" is of type Object or else null void hello(Object? name) hello(null); hello(1); hello("John Doe"); and which outputs: Hello, world! Hello, object 1! Hello, John Doe! String.size is 8 Kotlin See this example in Kotlin: fun hello(obj: Any) hello("Mooooo") Benefits This tech ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Off-side Rule
The off-side rule describes syntax of a computer programming language that defines the bounds of a code block via indentation. The term was coined by Peter Landin, possibly as a pun on the offside law in association football. An off-side rule language is contrasted with a free-form language in which indentation has no syntactic meaning, and indentation is strictly a matter of style. An off-side rule language is also described as having significant indentation. Definition Peter Landin, in his 1966 article " The Next 700 Programming Languages", defined the off-side rule thus: "Any non-whitespace token to the left of the first such token on the previous line is taken to be the start of a new declaration." Example The following is an example of indentation blocks in Python; a popular off-side rule language. In Python, the rule is taken to define the boundaries of statements rather than declarations. def is_even(a: int) -> bool: if a % 2 0: print('Eve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object-oriented Programming
Object-oriented programming (OOP) is a programming paradigm based on the concept of '' objects''. Objects can contain data (called fields, attributes or properties) and have actions they can perform (called procedures or methods and implemented in code). In OOP, computer programs are designed by making them out of objects that interact with one another. Many of the most widely used programming languages (such as C++, Java, and Python) support object-oriented programming to a greater or lesser degree, typically as part of multiple paradigms in combination with others such as imperative programming and declarative programming. Significant object-oriented languages include Ada, ActionScript, C++, Common Lisp, C#, Dart, Eiffel, Fortran 2003, Haxe, Java, JavaScript, Kotlin, Logo, MATLAB, Objective-C, Object Pascal, Perl, PHP, Python, R, Raku, Ruby, Scala, SIMSCRIPT, Simula, Smalltalk, Swift, Vala and Visual Basic.NET. History The idea of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syntax (programming Languages)
In computer science, the syntax of a computer language is the rules that define the combinations of symbols that are considered to be correctly structured Statement (computer science), statements or Expression (computer science), expressions in that language. This applies both to programming languages, where the document represents source code, and to markup languages, where the document represents data. The syntax of a language defines its surface form. Text-based user interface, Text-based computer languages are based on sequences of Character (computing), characters, while visual programming languages are based on the spatial layout and connections between symbols (which may be textual or graphical). Documents that are syntactically invalid are said to have a syntax error. When designing the syntax of a language, a designer might start by writing down examples of both legal and illegal String (computer science), strings, before trying to figure out the general rules from these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C Sharp (programming Language)
C# ( pronounced: C-sharp) ( ) is a general-purpose high-level programming language supporting multiple paradigms. C# encompasses static typing, strong typing, lexically scoped, imperative, declarative, functional, generic, object-oriented (class-based), and component-oriented programming disciplines. The principal inventors of the C# programming language were Anders Hejlsberg, Scott Wiltamuth, and Peter Golde from Microsoft. It was first widely distributed in July 2000 and was later approved as an international standard by Ecma (ECMA-334) in 2002 and ISO/ IEC (ISO/IEC 23270 and 20619) in 2003. Microsoft introduced C# along with .NET Framework and Microsoft Visual Studio, both of which are technically speaking, closed-source. At the time, Microsoft had no open-source products. Four years later, in 2004, a free and open-source project called Microsoft Mono began, providing a cross-platform compiler and runtime environment for the C# programming language. A decad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Modeling Language
The Java Modeling Language (JML) is a specification language for Java programs, using Hoare style pre- and postconditions and invariants, that follows the design by contract paradigm. Specifications are written as Java annotation comments to the source files, which hence can be compiled with any Java compiler. Various verification tools, such as a runtime assertion checker and the Extended Static Checker ( ESC/Java) aid development. Overview JML is a behavioural interface specification language for Java modules. JML provides semantics to formally describe the behavior of a Java module, preventing ambiguity with regard to the module designers' intentions. JML inherits ideas from Eiffel, Larch and the Refinement Calculus, with the goal of providing rigorous formal semantics while still being accessible to any Java programmer. Various tools are available that make use of JML's behavioral specifications. Because specifications can be written as annotations in Java program files, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frama-C
Frama-C is a set of interoperable program analyzers for C programs. The name ''Frama-C'' stands for ''Framework for Modular Analysis of C programs''. Frama-C has been developed by the French Commissariat à l'Énergie Atomique et aux Énergies Alternatives ( CEA-List) and Inria. It has also received funding from the Core Infrastructure Initiative. Frama-C, as a static analyzer, inspects programs without executing them. Despite its name, the software is not related to the French project Framasoft. Architecture Frama-C has a modular plugin architecture comparable to that of Eclipse (software) or GIMP. Frama-C relies on CIL ( C Intermediate Language) to generate an abstract syntax tree. The abstract syntax tree supports annotations written in ANSI/ISO C Specification Language (ACSL). Several modules can manipulate the abstract syntax tree to add ANSI/ISO C Specification Language (ACSL) annotations. Among frequently used plugins are: * ''Value analysis'' computes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dafny
Dafny is an imperative and functional compiled language that compiles to other programming languages, such as C#, Java, JavaScript, Go, and Python. It supports formal specification through preconditions, postconditions, loop invariants, loop variants, termination specifications and read/write framing specifications. The language combines ideas from the functional programming and imperative programming paradigms; it includes support for object-oriented programming. Features include ''generic classes'', ''dynamic allocation'', ''inductive datatypes'' and a variation of separation logic known as ''implicit dynamic frames'' for reasoning about side effects. Dafny was created by Rustan Leino at Microsoft Research after his prior work on developing ESC/Modula-3, ESC/Java, and Spec#. Dafny is regularly featured in software verification competitions (e.g. VSTTE'08, VSCOMP'10, COST'11, and VerifyThis'12). Dafny was designed as a verification-aware programming language, requiring ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ESC/Java
ESC/Java (and more recently ESC/Java2), the "Extended Static Checker for Java," is a programming tool that attempts to find common run-time errors in Java programs at compile time. The underlying approach used in ESC/Java is referred to as extended static checking, which is a collective name referring to a range of techniques for statically checking the correctness of various program constraints. For example, that an integer variable is greater-than-zero, or lies between the bounds of an array. This technique was pioneered in ESC/Java (and its predecessor, ESC/Modula-3) and can be thought of as an extended form of type checking. Extended static checking usually involves the use of an automated theorem prover and, in ESC/Java, the Simplify theorem prover was used. ESC/Java is neither sound nor complete. This was intentional and aims to reduce the number of errors and/or warnings reported to the programmer, in order to make the tool more useful in practice. However, it does ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SPARK (programming Language)
SPARK is a formally defined computer programming language based on the Ada language, intended for developing high integrity software used in systems where predictable and highly reliable operation is essential. It facilitates developing applications that demand safety, security, or business integrity. Originally, three versions of SPARK existed (SPARK83, SPARK95, SPARK2005), based on Ada 83, Ada 95, and Ada 2005 respectively. A fourth version, SPARK 2014, based on Ada 2012, was released on April 30, 2014. SPARK 2014 is a complete re-design of the language and supporting verification tools. The SPARK language consists of a well-defined subset of the Ada language that uses contracts to describe the specification of components in a form that is suitable for both static and dynamic verification. In SPARK83/95/2005, the contracts are encoded in Ada comments and so are ignored by any standard Ada compiler, but are processed by the SPARK ''Examiner'' and its associated tools. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Quality
In the context of software engineering, software quality refers to two related but distinct notions: * Software's functional quality reflects how well it complies with or conforms to a given design, based on functional requirements or specifications. That attribute can also be described as the fitness for the purpose of a piece of software or how it compares to competitors in the marketplace as a worthwhile product. It is the degree to which the correct software was produced. * Software structural quality refers to how it meets non-functional requirements that support the delivery of the functional requirements, such as robustness or maintainability. It has a lot more to do with the degree to which the software works as needed. Many aspects of structural quality can be evaluated only statically through the analysis of the software's inner structure, its source code (see Software metrics), at the unit level, and at the system level (sometimes referred to as end-to-end testin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
