functional programming

Delayed evaluation is used particularly in functional languages. When using delayed evaluation, an expression is not evaluated as soon as it gets bound to a variable, but when the evaluator is forced to produce the expression's value. Some programming languages delay evaluation of expressions by default, and some others provide functions or special syntax to delay evaluation. In Miranda and Haskell, evaluation of function arguments is delayed by default. In many other languages, evaluation can be delayed by explicitly suspending the computation using special syntax (as with Scheme's "delay" and "force") or, ...

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Lazy evaluation, Lazy evaluation - Delayed evaluation

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In most compiled programs, the local state of a function call, including its parameters and local variables, are stored in a data structure allocated from the stack. This activation record (in this case called a stack frame) is "pushed" when the function is called, and "popped", or deallocated, when the function returns. The upwards funarg problem arises because the funarg may refer to the local state of the function after that function has returned. Therefore, the activation record must not be deallocated when the function r ...

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Funarg problem, Funarg problem - Upwards funarg problem, Funarg problem - Downwards funarg problem, Funarg problem - Practical implications

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The term von Neumann architecture refers to a computer design model that uses a single storage structure to hold both instructions and data. The term von Neumann machine can be used to describe such a computer, but that term has other meanings as well. The separation of storage from the processing unit is implicit in the von Neumann architecture. The term "stored-program computer" is generally used to mean a computer of this design. Von Neumann architecture - History. The earliest computing machines ...

Including:

• Von Neumann architecture - History
• Von Neumann architecture - First Designs
• Von Neumann architecture - Von Neumann bottleneck
• Von Neumann architecture - Early stored-program computers
• Von Neumann architecture - Notes

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This article is about type polymorphism. For another kind of polymorphism in computer science, related only in name to type polymorphism, see polymorphic code. In computer science, polymorphism means allowing a single definition to be used with different types of data (specifically, different classes of objects). For instance, a polymorphic function definition can replace several type-specific ones, and a single polymorphic operator can act in expressions of various ...

Including:

• Polymorphism computer science - Parametric polymorphism
• Polymorphism computer science - Predicative and impredicative polymorphism
• Polymorphism computer science - Subtyping polymorphism
• Polymorphism computer science - Ad-hoc polymorphism
• Polymorphism computer science - Overloading
• Polymorphism computer science - Coercion
• Polymorphism computer science - Example
• Polymorphism computer science - Overloading
• Polymorphism computer science - Coercion
• Polymorphism computer science - Parametric polymorphism

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Alonzo Church (June 14, 1903 – August 11, 1995) was an American mathematician and logician who was responsible for some of the foundations of theoretical computer science. Born in Washington, DC, he received a bachelor's degree from Princeton University in 1924, completing his Ph.D. there in 1927, under Oswald Veblen. After a postdoc at Göttingen, he taught at Princeton, 1929-67, and at ...

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• Alonzo Church - Death
• Alonzo Church - Books

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Action at a distance is an anti-pattern (a recognized common error) in which behavior in one part of a program varies wildly based on difficult or impossible to identify operations in another part of the program. The way to avoid the problems associated with action at a distance are a proper design which avoids global variables and alters data in a controlled and local manner. The term is based on the physics concept of the same name, where particles may ...

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• Action at a distance computer science - Example
• Action at a distance computer science - Action at a distance across objects

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In mathematics and computer science an algorithm is a finite set of well-defined instructions for accomplishing some task which, given an initial state, will terminate in a corresponding recognizable end-state. Algorithms can be implemented by computer programs. Informally, the concept of an algorithm is often illustrated by the example of a recipe, although many algorithms are much more complex; algorithms often have steps that repeat (iterate) or require decisions (such as logic or comparison). The concept of algorithms was formalized in 1936 by Alan Turing's Turing machines and Alonzo Church's lambda c ...

Including:

• Algorithm - Formalization of algorithms
• Algorithm - Implementation
• Algorithm - Example
• Algorithm - History
• Algorithm - Classes
• Algorithm - Classification by implementation
• Algorithm - Classification by design paradigm
• Algorithm - Classification by field of study
• Algorithm - Classification by complexity
• Algorithm - Sources
• Algorithm - Legal issues

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In programming languages, a closure is an abstraction that combines a function and a special lexical environment bound to that function (scope). The variables in the lexical environment are designed to retain state information between function calls. Unlike garden-variety functions which retain no memory of what happened in previous calls, closures are capable of storing information across function calls. Closure lexical variables differ from global variables in that they do not occupy (or pollute) the global variable ...

Including:

• Closure computer science - Implementation and theory
• Closure computer science - Closures and functions
• Closure computer science - Uses of closures
• Closure computer science - Programming languages with closures
• Closure computer science - Simulating closures
• Closure computer science - Reference

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Category theory is a mathematical theory that deals in an abstract way with mathematical structures and relationships between them. It is half-jokingly known as "generalized abstract nonsense". Categories appear in most branches of mathematics, in some areas of theoretical computer science and mathematical physics, and have been a unifying notion. Categories were first introduced by Samuel Eilenberg and Saunders Ma ...

Including:

• Category theory - Background
• Category theory - Historical notes
• Category theory - Categories objects and morphisms
• Category theory - Some properties of morphisms
• Category theory - Functors
• Category theory - Natural transformations and isomorphisms
• Category theory - Universal constructions limits and colimits
• Category theory - Equivalent categories
• Category theory - Further concepts and results
• Category theory - Higher-dimensional categories

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Combinatory logic is a notation introduced by Moses Schönfinkel and Haskell Curry to eliminate the need for variables in mathematical logic. It has more recently been used in computer science as a theoretical model of computation and also as a basis for the design of functional programming languages. Combinatory logic - Combinatory logic in mathematics. Combinatory logic was intended as a simple 'pre-logic' which would clarify the meaning of variables in logical notation, and indeed eliminate the need for ...

Including:

• Combinatory logic - Combinatory logic in mathematics
• Combinatory logic - Combinatory logic in computing
• Combinatory logic - Summary of the lambda calculus
• Combinatory logic - Combinatory calculi
• Combinatory logic - Combinatory terms
• Combinatory logic - Examples of combinators
• Combinatory logic - Completeness of the S-K basis
• Combinatory logic - Simplifications of the transformation
• Combinatory logic - Reverse conversion
• Combinatory logic - Undecidability of combinatorial calculus
• Combinatory logic - Combinatory terms as graphs
• Combinatory logic - Applications
• Combinatory logic - Compilation of functional languages
• Combinatory logic - Logic

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For more information, please refer to discussion on this page and/or the listing at Wikipedia:Requested pictures. An environment is a complex of external factors. It acts on a system and determines its course and form of existence. An environment may be thought of as a superset, of which the given system is a subset. An environment may have one or more parameters, physical or otherwise. The environment of a given system must interact with t ...

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• Environment - Life science
• Environment - Physical science
• Environment - Liberal arts and social science
• Environment - Computer science and informatics

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Historically, the upwards funarg problem has proven to be the more difficult. For example, the Pascal programming language allows functions to be passed as arguments but not returned as results; thus implementations of Pascal are required to address the downwards funarg problem but not the upwards one. The C programming language avoids the main difficulty of the funarg problem by not allowing function definitions to be nested; because the environment of every function is the same, containing just the statically-allocated global variables and functions, a pointe ...

See also:

Funarg problem, Funarg problem - Upwards funarg problem, Funarg problem - Downwards funarg problem, Funarg problem - Practical implications

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A downwards funarg may also refer to a function's state when that function is not actually executing. However, because, by definition, the existence of a downwards funarg is contained in the execution of the function that creates it, the activation record for the function can usually still be stored on the stack. Nonetheless, the existence of downwards funargs implies a tree structure of closures and activation records that can comp ...

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Funarg problem, Funarg problem - Upwards funarg problem, Funarg problem - Downwards funarg problem, Funarg problem - Practical implications

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Lucid is a dataflow computer language designed to experiment with non-VonNeumann programming models. It was designed by Bill Wadge and Ed Ashcroft and described in the book Lucid, the Dataflow Programming Language. It employed several techniques from functional programming. Several languages evolved from Lucid. Original Lucid is no longer maintained or used. Lucid is also the surname of astronaut Shannon Lucid. ...

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Measure can mean: To perform a measurement. In mathematics, a measure is a way to assign non-negative real numbers to subsets of a given set, in order to "measure their sizes or probabilities". See measure (mathematics) for a treatment of the concept. In music, a measure is a unit of time in Western music usually equalling the metric unit length. It represents a regular grouping of beats, a meter, as indicated in musical notation by the time signature. Measures are also called bars,

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A Unix shell, also called "the command line", provides the traditional user interface for the Unix operating system. Users direct the operation of the computer by entering command input as text for a shell to execute. Within the Microsoft Windows suite of operating systems the analogous program is command.com, or cmd.exe for Windows NT-based operating systems. The most generic sense of the term shell means any program that users use to type commands; it is called a "shell" because it hides the details of the under ...

Including:

• Unix shell - Unix shells
• Unix shell - Bourne shell compatible
• Unix shell - C shell compatible
• Unix shell - Other
• Unix shell - Historic

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Unix shell - Bourne shell compatible. Bourne shell (sh) Written by Steve Bourne, while at Bell Labs. First distributed with Version 7 Unix, circa 1978. Almquist shell (ash) Bourne-Again shell (bash) Korn shell (ksh) Written by David Korn, while at Bell Labs. Z shell (zsh) Unix shell - C shell compatible. C shell (csh) Written by Bill Joy, while at the University of California, Berkeley. First distributed with BSD, circa 1979. < ...

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Unix shell, Unix shell - Unix shells, Unix shell - Bourne shell compatible, Unix shell - C shell compatible, Unix shell - Other, Unix shell - Historic

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Parameter - Mathematical. In mathematics, the difference in meaning between a parameter and an argument of a function is that the parameters are the symbols that are part of the function's definition, while arguments are the symbols that are supplied to the function when it is used. The value or objects assigned to the parameters by the corresponding arguments of a function or system are not reassigned during the function's evaluation. So, parameters are effectively constants during th ...

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Parameter, Parameter - Types of parameter, Parameter - Mathematical, Parameter - Computer science, Parameter - Logic, Parameter - Engineering, Parameter - Analytic geometry, Parameter - Mathematical analysis, Parameter - Probability theory, Parameter - Statistics

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The modern idea of a mathematical function was introduced by Leibniz, and the associated notation y = f(x) was invented by Leonhard Euler, in the 18th century. But the intuitive idea of a function as any rule or procedure that assigns an output to each given input proved to be naive. Joseph Fourier, for example, claimed that every function had a Fourier series, something no mathematician would claim today. The concept of a function was not put on a rigorous basis u ...

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Function mathematics, Function mathematics - Introduction, Function mathematics - Functions of more than one variable, Function mathematics - History, Function mathematics - Formal definition, Function mathematics - Domains codomains and ranges, Function mathematics - Injective surjective and bijective functions, Function mathematics - Images and preimages, Function mathematics - Graph of a function, Function mathematics - Examples of functions, Function mathematics - Properties of functions, Function mathematics - Ambiguous functions, Function mathematics - n-ary function: function of several variables, Function mathematics - Composing functions, Function mathematics - Inverse function, Function mathematics - Restrictions and extensions, Function mathematics - Pointwise operations, Function mathematics - Computable and non-computable functions, Function mathematics - Functions from the categorical viewpoint

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The following Mathematica sequence will find the determinant of the 6×6 matrix whose i, j'th entry contains ij with all zero entries replaced as 1. In[1]:= Det[Array[Times, {6, 6}, 0] /. 0 -> 1] Out[1]= 0 So the determinant of such a matrix is 0. The following numerically calculates the root of the equation ex = x2 + 2, starting at the point x = -1. In[2]:= FindRoot[Exp[x] == x^2 + 2, {x, -1}] Out[2]= {x -> 1.3190736768573652} See Hello World f ...

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Mathematica, Mathematica - Overview, Mathematica - Examples, Mathematica - Multiple paradigms one language, Mathematica - Common structures common manipulations, Mathematica - Front ends, Mathematica - Connections with other applications, Mathematica - Mathematica on the Web

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