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Assertion (programming)
In computer programming, specifically when using the imperative programming paradigm, an assertion is a predicate (a Boolean-valued function over the state space, usually expressed as a logical proposition using the variables of a program) connected to a point in the program, that always should evaluate to true at that point in code execution. Assertions can help a programmer read the code, help a compiler compile it, or help the program detect its own defects. For the latter, some programs check assertions by actually evaluating the predicate as they run. Then, if it is not in fact true – an assertion failure – the program considers itself to be broken and typically deliberately crashes or throws an assertion failure exception. Details The following code contains two assertions, x > 0 and x > 1, and they are indeed true at the indicated points during execution: x = 1; assert x > 0; x++; assert x > 1; Programmers can use assertions to help specify programs and to re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Security Assertion Markup Language
Security Assertion Markup Language (SAML, pronounced ''SAM-el'', ) is an open standard for exchanging authentication and authorization data between parties, in particular, between an identity provider and a service provider. SAML is an XML-based markup language for security assertions (statements that service providers use to make access-control decisions). SAML is also: * A set of XML-based protocol messages * A set of protocol message bindings * A set of profiles (utilizing all of the above) An important use case that SAML addresses is web-browser single sign-on (SSO). Single sign-on is relatively easy to accomplish within a security domain (using cookies, for example) but extending SSO across security domains is more difficult and resulted in the proliferation of non-interoperable proprietary technologies. The SAML Web Browser SSO profile was specified and standardized to promote interoperability.J. Hughes et al. ''Profiles for the OASIS Security Assertion Markup Langu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Statement (programming)
In computer programming, a statement is a syntactic unit of an imperative programming language that expresses some action to be carried out. A program written in such a language is formed by a sequence of one or more statements. A statement may have internal components (e.g. expressions). Many programming languages (e.g. Ada, Algol 60, C, Java, Pascal) make a distinction between statements and definitions/declarations. A definition or declaration specifies the data on which a program is to operate, while a statement specifies the actions to be taken with that data. Statements which cannot contain other statements are ''simple''; those which can contain other statements are ''compound''. The appearance of a statement (and indeed a program) is determined by its syntax or grammar. The meaning of a statement is determined by its semantics. Simple statements Simple statements are complete in themselves; these include assignments, subroutine calls, and a few statements which may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assert
Assertion or assert may refer to: Computing * Assertion (software development), a computer programming technique * assert.h, a header file in the standard library of the C programming language * Assertion definition language, a specification language providing a formal grammar to specify behaviour and interfaces for computer software Logic and language * Logical assertion, a statement that asserts that a certain premise is true * Proof by assertion, an informal fallacy in which a proposition is repeatedly restated * Time of assertion, in linguistics a secondary temporal reference in establishing tense * Assertive, a speech act In the philosophy of language and linguistics, a speech act is something expressed by an individual that not only presents information but performs an action as well. For example, the phrase "I would like the mashed potatoes; could you please pas ... that commits a speaker to the truth of the expressed proposition Other uses * Assert (horse) (1979– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D (programming Language)
D, also known as dlang, is a multi-paradigm system programming language created by Walter Bright at Digital Mars and released in 2001. Andrei Alexandrescu joined the design and development effort in 2007. Though it originated as a re-engineering of C++, D is now a very different language. As it has developed, it has drawn inspiration from other high-level programming languages. Notably, it has been influenced by Java, Python, Ruby, C#, and Eiffel. The D language reference describes it as follows: Features D is not source-compatible with C and C++ source code in general. However, any code that is legal in both C/C++ and D should behave in the same way. Like C++, D has closures, anonymous functions, compile-time function execution, design by contract, ranges, built-in container iteration concepts, and type inference. D's declaration, statement and expression syntaxes also closely match those of C++. Unlike C++, D also implements garbage collection, first cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modulo Operation
In computing and mathematics, the modulo operation returns the remainder or signed remainder of a Division (mathematics), division, after one number is divided by another, the latter being called the ''modular arithmetic, modulus'' of the operation. Given two positive numbers and , modulo (often abbreviated as ) is the remainder of the Euclidean division of by , where is the Division (mathematics), dividend and is the divisor. For example, the expression "5 mod 2" evaluates to 1, because 5 divided by 2 has a quotient of 2 and a remainder of 1, while "9 mod 3" would evaluate to 0, because 9 divided by 3 has a quotient of 3 and a remainder of 0. Although typically performed with and both being integers, many computing systems now allow other types of numeric operands. The range of values for an integer modulo operation of is 0 to . mod 1 is always 0. When exactly one of or is negative, the basic definition breaks down, and programming languages differ in how these valu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remainder
In mathematics, the remainder is the amount "left over" after performing some computation. In arithmetic, the remainder is the integer "left over" after dividing one integer by another to produce an integer quotient ( integer division). In algebra of polynomials, the remainder is the polynomial "left over" after dividing one polynomial by another. The ''modulo operation'' is the operation that produces such a remainder when given a dividend and divisor. Alternatively, a remainder is also what is left after subtracting one number from another, although this is more precisely called the '' difference''. This usage can be found in some elementary textbooks; colloquially it is replaced by the expression "the rest" as in "Give me two dollars back and keep the rest." However, the term "remainder" is still used in this sense when a function is approximated by a series expansion, where the error expression ("the rest") is referred to as the remainder term. Integer division Gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comment (computer Programming)
In computer programming, a comment is text embedded in source code that a translator (compiler or interpreter (computing), interpreter) ignores. Generally, a comment is an annotation intended to make the code easier for a programmer to understand often explaining an aspect that is not readily apparent in the program (non-comment) code. For this article, ''comment'' refers to the same concept in a programming language, markup language, configuration file and any similar context. Some development tools, other than a source code translator, do parse comments to provide capabilities such as API documentation generator, document generation, static analysis, and version control integration. The comparison of programming languages (syntax)#Comments, syntax of comments varies by programming language yet there are repeating patterns in the syntax among languages as well as similar aspects related to comment content. The flexibility supported by comments allows for a wide degree of cont ... [...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] |
Class (computer Science)
In object-oriented programming, a class defines the shared aspects of objects created from the class. The capabilities of a class differ between programming languages, but generally the shared aspects consist of state ( variables) and behavior ( methods) that are each either associated with a particular object or with all objects of that class. Object state can differ between each instance of the class whereas the class state is shared by all of them. The object methods include access to the object state (via an implicit or explicit parameter that references the object) whereas class methods do not. If the language supports inheritance, a class can be defined based on another class with all of its state and behavior plus additional state and behavior that further specializes the class. The specialized class is a ''sub-class'', and the class it is based on is its ''superclass''. Attributes Object lifecycle As an instance of a class, an object is constructed from a class via '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invariant (computer Science)
In mathematics, an invariant is a property of a mathematical object (or a class of mathematical objects) which remains unchanged after operations or transformations of a certain type are applied to the objects. The particular class of objects and type of transformations are usually indicated by the context in which the term is used. For example, the area of a triangle is an invariant with respect to isometries of the Euclidean plane. The phrases "invariant under" and "invariant to" a transformation are both used. More generally, an invariant with respect to an equivalence relation is a property that is constant on each equivalence class. Invariants are used in diverse areas of mathematics such as geometry, topology, algebra and discrete mathematics. Some important classes of transformations are defined by an invariant they leave unchanged. For example, conformal maps are defined as transformations of the plane that preserve angles. The discovery of invariants is an important ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Runtime System
In computer programming, a runtime system or runtime environment is a sub-system that exists in the computer where a program is created, as well as in the computers where the program is intended to be run. The name comes from the compile time and runtime division from compiled languages, which similarly distinguishes the computer processes involved in the creation of a program (compilation) and its execution in the target machine (the runtime). Most programming languages have some form of runtime system that provides an environment in which programs run. This environment may address a number of issues including the management of application memory, how the program accesses variables, mechanisms for passing parameters between procedures, interfacing with the operating system (OS), among others. The compiler makes assumptions depending on the specific runtime system to generate correct code. Typically the runtime system will have some responsibility for setting up and managin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java (programming Language)
Java is a High-level programming language, high-level, General-purpose programming language, general-purpose, Memory safety, memory-safe, object-oriented programming, object-oriented programming language. It is intended to let programmers ''write once, run anywhere'' (Write once, run anywhere, WORA), meaning that compiler, compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to Java bytecode, bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax (programming languages), syntax of Java is similar to C (programming language), C and C++, but has fewer low-level programming language, low-level facilities than either of them. The Java runtime provides dynamic capabilities (such as Reflective programming, reflection and runtime code modification) that are typically not available in traditional compiled languages. Java gained popularity sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
