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Typestate Analysis
Typestate analysis, sometimes called protocol analysis, is a form of program analysis employed in programming languages. It is most commonly applied to object-oriented languages. Typestates define valid sequences of operations that can be performed upon an instance of a given type. Typestates, as the name suggests, associate state information with variables of that type. This state information is used to determine at compile-time which operations are valid to be invoked upon an instance of the type. Operations performed on an object that would usually only be executed at run-time are performed upon the type state information which is modified to be compatible with the new state of the object. Typestates are capable of representing behavioral type refinements such as "method ''A'' must be invoked before method ''B'' is invoked, and method ''C'' may not be invoked in between". Typestates are well-suited to representing resources that use open/close semantics by enforcing semantically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Program Analysis
In computer science, program analysis is the process of analyzing the behavior of computer programs regarding a property such as correctness, robustness, safety and liveness. Program analysis focuses on two major areas: program optimization and program correctness. The first focuses on improving the program’s performance while reducing the resource usage while the latter focuses on ensuring that the program does what it is supposed to do. Program analysis can be performed without executing the program ( static program analysis), during runtime (dynamic program analysis) or in a combination of both. Static program analysis In the context of program correctness, static analysis can discover vulnerabilities during the development phase of the program.Jovanovic, N., Kruegel, C., & Kirda, E. (2006, May). Pixy: A static analysis tool for detecting web application vulnerabilities. In Security and Privacy, 2006 IEEE Symposium on (pp. 6-pp). IEEE. These vulnerabilities are easier t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Covering Relation
In mathematics, especially order theory, the covering relation of a partially ordered set is the binary relation which holds between comparable elements that are immediate neighbours. The covering relation is commonly used to graphically express the partial order by means of the Hasse diagram. Definition Let X be a set with a partial order \le. As usual, let < be the relation on such that |
Effect System
In computing, an effect system is a formal system that describes the computational effects of computer programs, such as side effects. An effect system can be used to provide a compile-time check of the possible effects of the program. The effect system extends the notion of type to have an "effect" component, which comprises an effect kind and a region. The effect kind describes ''what'' is being done, and the region describes ''with what'' (parameters) it is being done. An effect system is typically an extension of a type system. The term "type and effect system" is sometimes used in this case. Often, a type of a value is denoted together with its effect as ''type ! effect'', where both the type component and the effect component mention certain regions (for example, a type of a mutable memory cell is parameterized by the label of the memory region in which the cell resides). The term "algebraic effect" follows from the type system. Effect systems may be used to prove the exte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Type System
Substructural type systems are a family of type systems analogous to substructural logics where one or more of the structural rules are absent or only allowed under controlled circumstances. Such systems can constrain access to system resources such as files, locks, and memory by keeping track of changes of state and prohibiting invalid states. Different substructural type systems Several type systems have emerged by discarding some of the structural rules of exchange, weakening, and contraction: *''Ordered type systems'' (discard exchange, weakening and contraction): Every variable is used exactly once in the order it was introduced. *''Linear type systems'' (allow exchange, but neither weakening nor contraction): Every variable is used exactly once. *''Affine type systems'' (allow exchange and weakening, but not contraction): Every variable is used at most once. *''Relevant type systems'' (allow exchange and contraction, but not weakening): Every variable is used at le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Design By Contract
Design by contract (DbC), also known as contract programming, programming by contract and design-by-contract programming, is an approach for designing software. It prescribes that software designers should define formal, precise and verifiable interface specifications for software components, which extend the ordinary definition of abstract data types with preconditions, postconditions and invariants. These specifications are referred to as "contracts", in accordance with a conceptual metaphor with the conditions and obligations of business contracts. The DbC approach assumes all ''client components'' that invoke an operation on a ''server component'' will meet the preconditions specified as required for that operation. Where this assumption is considered too risky (as in multi-channel or distributed computing), the inverse approach is taken, meaning that the ''server component'' tests that all relevant preconditions hold true (before, or while, processing the ''client co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
State Pattern
The state pattern is a Behavioral pattern, behavioral software design pattern that allows an object to alter its behavior when its internal state changes. This pattern is close to the concept of finite-state machines. The state pattern can be interpreted as a strategy pattern, which is able to switch a strategy through invocations of methods defined in the pattern's interface. The state pattern is used in computer programming to encapsulate varying behavior for the same object (computer science), object, based on its internal state. This can be a cleaner way for an object to change its behavior at runtime without resorting to conditional statements and thus improve maintainability. Overview The state design pattern is one of twenty-three Design Patterns, design patterns documented by the Gang of Four that describe how to solve recurring design problems. Such problems cover the design of flexible and reusable object-oriented software, such as objects that are easy to implement, cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATS (programming Language)
In computing, ATS (Applied Type System) is a multi-paradigm, general-purpose, high-level, functional programming language. It is a dialect of the programming language ML, designed by Hongwei Xi to unify computer programming with formal specification. ATS has support for combining theorem proving with practical programming through the use of advanced type systems. A past version of The Computer Language Benchmarks Game has demonstrated that the performance of ATS is comparable to that of the languages C and C++. By using theorem proving and strict type checking, the compiler can detect and prove that its implemented functions are not susceptible to bugs such as division by zero, memory leaks, buffer overflow, and other forms of memory corruption by verifying pointer arithmetic and reference counting before the program runs. Also, by using the integrated theorem-proving system of ATS (ATS/LF), the programmer may make use of static constructs that are intertwined with th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rust (programming Language)
Rust is a General-purpose programming language, general-purpose programming language emphasizing Computer performance, performance, type safety, and Concurrency (computer science), concurrency. It enforces memory safety, meaning that all Reference (computer science), references point to valid memory. It does so without a conventional Garbage collection (computer science), garbage collector; instead, memory safety errors and data races are prevented by the "borrow checker", which tracks the object lifetime of references Compiler, at compile time. Rust does not enforce a programming paradigm, but was influenced by ideas from functional programming, including Immutable object, immutability, higher-order functions, algebraic data types, and pattern matching. It also supports object-oriented programming via structs, Enumerated type, enums, traits, and methods. It is popular for systems programming. Software developer Graydon Hoare created Rust as a personal project while working at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnegie Mellon University
Carnegie Mellon University (CMU) is a private research university in Pittsburgh, Pennsylvania, United States. The institution was established in 1900 by Andrew Carnegie as the Carnegie Technical Schools. In 1912, it became the Carnegie Institute of Technology and began granting four-year degrees. In 1967, it became Carnegie Mellon University through its merger with the Mellon Institute of Industrial Research, founded in 1913 by Andrew Mellon and Richard B. Mellon and formerly a part of the University of Pittsburgh. The university consists of seven colleges, including the College of Engineering, the School of Computer Science, and the Tepper School of Business. The university has its main campus located 5 miles (8 km) from downtown Pittsburgh. It also has over a dozen degree-granting locations in six continents, including campuses in Qatar, Silicon Valley, and Kigali, Rwanda ( Carnegie Mellon University Africa) and partnerships with universities nationally and glob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corina Păsăreanu
Corina S. Păsăreanu is a Romanian-American computer scientist with affiliations at the NASA Ames Research Center, with the Carnegie Mellon University CyLab Security and Privacy Institute, and with KBR. Her research involves formal methods, including symbolic execution and the verification of systems of interacting components. She is the author of the book ''Symbolic Execution and Quantitative Reasoning: Applications to Software Safety and Security'' (Springer, 2022). Education Păsăreanu studied computer science at the Politehnica University of Bucharest, where she earned a bachelor's degree in 1994 and a master's degree in 1995. She earned her Ph.D. in 2001, at Kansas State University, with the dissertation ''Abstraction and Modular Reasoning for the Verification of Software'' supervised by Matthew B. Dwyer. Recognition In 2010, a paper coauthored by Păsăreanu in 1998 on extracting finite-state models from compiled computer code, suitable for use in model checking, won th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aliasing (computing)
In computing, aliasing describes a situation in which a data location in memory can be accessed through different symbolic names in the program. Thus, modifying the data through one name implicitly modifies the values associated with all aliased names, which may not be expected by the programmer. As a result, aliasing makes it particularly difficult to understand, analyze and optimize programs. Aliasing analysers intend to make and compute useful information for understanding aliasing in programs. Aliased pointers Aliasing can occur in any language that can refer to one location in memory with more than one name (for example, with pointers). This is a common problem with functions that accept pointer arguments, and their tolerance (or the lack thereof) for aliasing must be carefully documented, particularly for functions that perform complex manipulations on memory areas passed to them. Specified aliasing Controlled aliasing behaviour may be desirable in some cases (that is, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear-time
In theoretical computer science, the time complexity is the computational complexity that describes the amount of computer time it takes to run an algorithm. Time complexity is commonly estimated by counting the number of elementary operations performed by the algorithm, supposing that each elementary operation takes a fixed amount of time to perform. Thus, the amount of time taken and the number of elementary operations performed by the algorithm are taken to be related by a constant factor. Since an algorithm's running time may vary among different inputs of the same size, one commonly considers the worst-case time complexity, which is the maximum amount of time required for inputs of a given size. Less common, and usually specified explicitly, is the average-case complexity, which is the average of the time taken on inputs of a given size (this makes sense because there are only a finite number of possible inputs of a given size). In both cases, the time complexity is genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
