Nominal Typing
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Nominal Typing
In computer science, a type system is nominal (also called nominative or name-based) if compatibility and equivalence of data types is determined by explicit declarations and/or the name of the types. Nominal systems are used to determine whether types are equivalent, as well as whether a type is a subtype of another. Nominal type systems contrast with ''structural systems'', where comparisons are based on the structure of the types in question and do not require explicit declarations. Nominal typing Nominal typing means that two variables are type-compatible if and only if their declarations name the same type. For example, in C, two struct types with different names in the same translation unit are never considered compatible, even if they have identical field declarations. However, C also allows a typedef declaration, which introduces an alias for an existing type. These are merely syntactical and do not differentiate the type from its alias for the purpose of type checki ...
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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 ...
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Kotlin (programming Language)
Kotlin () is a Cross-platform software, cross-platform, static typing, statically typed, general-purpose programming language, general-purpose High-level programming language, high-level programming language with type inference. Kotlin is designed to interoperate fully with Java (programming language), Java, and the Java virtual machine, JVM version of Kotlin's standard library depends on the Java Class Library, but type inference allows its syntax (programming languages), syntax to be more concise. Kotlin mainly targets the JVM, but also compiles to JavaScript (e.g., for frontend web applications using React (software), React) or machine code, native code via LLVM (e.g., for native iOS apps sharing business logic with Android (operating system), Android apps). Language development costs are borne by JetBrains, while the Kotlin Foundation protects the Kotlin trademark. On 7 May 2019, Google announced that the Kotlin programming language had become its preferred language for Andro ...
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Types And Programming Languages
''Types and Programming Languages'', written by Benjamin C. Pierce who is a Professor of Computer and Information Science at the University of Pennsylvania is a computing book on type systems and programming languages. ''Types and Programming Languages'' was published in 2002 by MIT Press. Since its publication, the book has become one of the most widely cited and influential texts in the field of programming language theory. It is frequently used as a graduate-level textbook A textbook is a book containing a comprehensive compilation of content in a branch of study with the intention of explaining it. Textbooks are produced to meet the needs of educators, usually at educational institutions, but also of learners ( ... in computer science programs around the world and has shaped the way type systems are taught in academic curricula. A review by Frank Pfenning called it "probably the single most important book in the area of programming languages in recent years." Ref ...
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Type System
In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a ''type'' (for example, integer, floating point, string) to every '' term'' (a word, phrase, or other set of symbols). Usually the terms are various language constructs of a computer program, such as variables, expressions, functions, or modules. A type system dictates the operations that can be performed on a term. For variables, the type system determines the allowed values of that term. Type systems formalize and enforce the otherwise implicit categories the programmer uses for algebraic data types, data structures, or other data types, such as "string", "array of float", "function returning boolean". Type systems are often specified as part of programming languages and built into interpreters and compilers, although the type system of a language can be extended by optional tools that perform added checks using the language's original type synta ...
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Abstract Type
In programming languages, an abstract type (also known as existential types) is a type in a nominative type system that cannot be instantiated directly; by contrast, a concrete type be instantiated directly. Instantiation of an abstract type can occur only indirectly, via a concrete ''subtype''. An abstract type may provide no implementation, or an incomplete implementation. In some languages, abstract types with no implementation (rather than an incomplete implementation) are known as '' protocols'', ''interfaces'', ''signatures'', or ''class types''. In class-based object-oriented programming, abstract types are implemented as '' abstract classes'' (also known as '' abstract base classes''), and concrete types as '' concrete classes''. In generic programming, the analogous notion is a ''concept'', which similarly specifies syntax and semantics, but does not require a subtype relationship: two unrelated types may satisfy the same concept. Often, abstract types will h ...
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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 ...
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Julia (programming Language)
Julia is a high-level programming language, high-level, general-purpose programming language, general-purpose dynamic programming language, dynamic programming language, designed to be fast and productive, for e.g. data science, artificial intelligence, machine learning, modeling and simulation, most commonly used for numerical analysis and computational science. Distinctive aspects of Julia's design include a type system with parametric polymorphism and the use of multiple dispatch as a core programming paradigm, a default just-in-time compilation, just-in-time (JIT) compiler (with support for ahead-of-time compilation) and an tracing garbage collection, efficient (multi-threaded) garbage collection implementation. Notably Julia does not support classes with encapsulated methods and instead it relies on structs with generic methods/functions not tied to them. By default, Julia is run similarly to scripting languages, using its runtime, and allows for read–eval–print loop, i ...
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Swift (programming Language)
Swift is a High-level programming language, high-level general-purpose programming language, general-purpose, multi-paradigm programming language, multi-paradigm, compiled language, compiled programming language created by Chris Lattner in 2010 for Apple Inc. and maintained by Open-source software movement, the open-source community. Swift compiles to machine code and uses an LLVM-based compiler. Swift was first released in June 2014 and the Swift toolchain has shipped in Xcode since Xcode version 6, released in September 2014. Apple intended Swift to support many core concepts associated with Objective-C, notably dynamic dispatch, widespread late binding, extensible programming, and similar features, but in a "safer" way, making it easier to catch software bugs; Swift has features addressing some common programming errors like null pointer Dereference operator, dereferencing and provides syntactic sugar to help avoid the Pyramid of doom (programming), pyramid of doom. Swift sup ...
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Delphi (programming Language)
Delphi is a general-purpose programming language and a software product that uses the Delphi dialect of the Object Pascal programming language and provides an integrated development environment (IDE) for rapid application development of desktop, mobile application, mobile, web application, web, and console application, console software, currently developed and maintained by Embarcadero Technologies. Delphi's compilers generate native code for Microsoft Windows, macOS, iOS, Android (operating system), Android and Linux (X86-64, x64). Delphi includes a code editor, a visual designer, an integrated debugger, a Version control, source code control component, and support for third-party Plugin (computing), plugins. The code editor features Code Insight (code completion), Error Insight (real-time error-checking), and Code refactoring, refactoring. The visual forms designer has the option of using either the Visual Component Library (VCL) for pure Windows development or the FireMonkey ...
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Objective-C
Objective-C is a high-level general-purpose, object-oriented programming language that adds Smalltalk-style message passing (messaging) to the C programming language. Originally developed by Brad Cox and Tom Love in the early 1980s, it was selected by NeXT for its NeXTSTEP operating system. Due to Apple macOS’s direct lineage from NeXTSTEP, Objective-C was the standard language used, supported, and promoted by Apple for developing macOS and iOS applications (via their respective application programming interfaces ( APIs), Cocoa and Cocoa Touch) from 1997, when Apple purchased NeXT until the introduction of the Swift language in 2014. Objective-C programs developed for non-Apple operating systems or that are not dependent on Apple's APIs may also be compiled for any platform supported by GNU GNU Compiler Collection (GCC) or LLVM/ Clang. Objective-C source code 'messaging/implementation' program files usually have filename extensions, while Objective-C 'header/ ...
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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 ...
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Type System
In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a ''type'' (for example, integer, floating point, string) to every '' term'' (a word, phrase, or other set of symbols). Usually the terms are various language constructs of a computer program, such as variables, expressions, functions, or modules. A type system dictates the operations that can be performed on a term. For variables, the type system determines the allowed values of that term. Type systems formalize and enforce the otherwise implicit categories the programmer uses for algebraic data types, data structures, or other data types, such as "string", "array of float", "function returning boolean". Type systems are often specified as part of programming languages and built into interpreters and compilers, although the type system of a language can be extended by optional tools that perform added checks using the language's original type synta ...
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