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Value Semantics
In computer science, having value semantics (also value-type semantics or copy-by-value semantics) means for an object that only its value counts, not its identity. Immutable objects have value semantics trivially, and in the presence of mutation, an object with value semantics can only be uniquely-referenced at any point in a program. The concepts that are used to explain this concept are extensionality, definiteness, substitutivity of identity, unfoldability, and referential transparency In analytic philosophy and computer science, referential transparency and referential opacity are properties of linguistic constructions, and by extension of languages. A linguistic construction is called ''referentially transparent'' when for an .... References Programming paradigms {{Compu-prog-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Science
Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, applied disciplines (including the design and implementation of Computer architecture, hardware and Software engineering, software). Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of computational problem, problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and preventing security vulnerabilities. Computer graphics (computer science), Computer graphics and computational geometry address the generation of images. Programming language theory considers different ways to describe computational processes, and database theory concerns the management of re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immutability
In object-oriented (OO) and functional programming, an immutable object (unchangeable object) is an object whose state cannot be modified after it is created.Goetz et al. ''Java Concurrency in Practice''. Addison Wesley Professional, 2006, Section 3.4. Immutability This is in contrast to a mutable object (changeable object), which can be modified after it is created. In some cases, an object is considered immutable even if some internally used attributes change, but the object's state appears unchanging from an external point of view. For example, an object that uses to cache the results of expensive computations could still be considered an immutable object. Strings and other concrete objects are typically expressed as immutable objects to improve readability and runtime efficiency in object-oriented programming. Immutable objects are also useful because they are inherently thread-safe. Other benefits are that they are simpler to understand and reason about and offer higher se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extensionality
In logic, extensionality, or extensional equality, refers to principles that judge objects to be equality (mathematics), equal if they have the same external properties. It stands in contrast to the concept of intensionality, which is concerned with whether the internal definitions of objects are the same. In mathematics The extensional definition of function equality, discussed above, is commonly used in mathematics. A similar extensional definition is usually employed for relation (mathematics), relations: two relations are said to be equal if they have the same Extension (predicate logic), extensions. In set theory, the axiom of extensionality states that two set (mathematics), sets are equal if and only if they contain the same elements. In mathematics formalized in set theory, it is common to identify relations—and, most importantly, function (mathematics), functions—with their extension as stated above, so that it is impossible for two relations or functions with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Definiteness (Computer Science)
In linguistics, definiteness is a semantic feature of noun phrases that distinguishes between referents or senses that are identifiable in a given context (definite noun phrases) and those that are not (indefinite noun phrases). The prototypical definite noun phrase picks out a unique, familiar, specific referent such as ''the sun'' or ''Australia'', as opposed to indefinite examples like ''an idea'' or ''some fish''. There is considerable variation in the expression of definiteness across languages, and some languages such as Japanese do not generally mark it, so the same expression can be definite in some contexts and indefinite in others. In other languages, such as English, it is usually marked by the selection of determiner (e.g., ''the'' vs. ''a''). Still other languages, such as Danish, mark definiteness morphologically by changing the noun itself (e.g. Danish ''en'' ''mand'' (a man), ''manden'' (the man)). Definiteness as a grammatical category There are times when a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
