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Strictness Analysis
In computer science, strictness analysis refers to any algorithm used to prove that a function in a non-strict functional programming language is strict in one or more of its arguments. This information is useful to compilers because strict functions can be compiled more efficiently. Thus, if a function is proven to be strict (using strictness analysis) at compile time, it can be compiled to use a more efficient calling convention without changing the meaning of the enclosing program. Note that a function f is said to ''diverge'' if it returns \: operationally, that would mean that f either causes abnormal termination of the enclosing program (e.g., failure with an error message) or that it loops infinitely. The notion of "divergence" is significant because a strict function is one that always diverges when given an argument that diverges, whereas a lazy (or non-strict) function is one that may or may not diverge when given such an argument. Strictness analysis attempts to determin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical disciplines (including the design and implementation of Computer architecture, hardware and Computer programming, software). Computer science is generally considered an area of research, academic research and distinct from computer programming. 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 for preventing Vulnerability (computing), security vulnerabilities. Computer graphics (computer science), Computer graphics and computational geometry address the generation of images. Progr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-strict Programming Language
A strict programming language is a programming language which employs a strict programming paradigm, allowing only strict functions (functions whose parameters must be evaluated completely before they may be called) to be defined by the user. A non-strict programming language allows the user to define non-strict functions, and hence may allow lazy evaluation. Examples Nearly all programming languages in common use today are strict. Examples include C#, Java, Perl (all versions, i.e. through version 5 and version 7), Python, Ruby, Common Lisp, and ML. Some strict programming languages include features that mimic laziness. Raku, formerly known as Perl 6, has lazy lists. Python has generator functions. Julia provides a macro system to build non-strict functions, as does Scheme. Examples for non-strict languages are Haskell, Miranda, and Clean. Explanation In most non-strict languages the non-strictness extends to data constructors. This allows conceptually infinite data ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Programming
In computer science, functional programming is a programming paradigm where programs are constructed by Function application, applying and Function composition (computer science), composing Function (computer science), functions. It is a declarative programming paradigm in which function definitions are Tree (data structure), trees of Expression (computer science), expressions that map Value (computer science), values to other values, rather than a sequence of Imperative programming, imperative Statement (computer science), statements which update the State (computer science), running state of the program. In functional programming, functions are treated as first-class citizens, meaning that they can be bound to names (including local Identifier (computer languages), identifiers), passed as Parameter (computer programming), arguments, and Return value, returned from other functions, just as any other data type can. This allows programs to be written in a Declarative programming, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strict Function
In computer science and computer programming, a function f is said to be strict if, when applied to a non-terminating expression, it also fails to terminate. A strict function in the denotational semantics of programming languages is a function ''f'' where f\left(\perp\right) = \perp. The entity \perp, called ''bottom'', denotes an expression that does not return a normal value, either because it loops endlessly or because it aborts due to an error such as division by zero. A function that is not strict is called non-strict. A strict programming language is one in which user-defined functions are always strict. Intuitively, non-strict functions correspond to control structures. Operationally, a strict function is one that always evaluates its argument; a non-strict function is one that might not evaluate some of its arguments. Functions having more than one parameter can be strict or non-strict in each parameter independently, as well as ''jointly strict'' in several parameters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compiler
In computing, a compiler is a computer program that translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primarily used for programs that translate source code from a high-level programming language to a low-level programming language (e.g. assembly language, object code, or machine code) to create an executable program. Compilers: Principles, Techniques, and Tools by Alfred V. Aho, Ravi Sethi, Jeffrey D. Ullman - Second Edition, 2007 There are many different types of compilers which produce output in different useful forms. A ''cross-compiler'' produces code for a different CPU or operating system than the one on which the cross-compiler itself runs. A ''bootstrap compiler'' is often a temporary compiler, used for compiling a more permanent or better optimised compiler for a language. Related software include, a program that translates from a low-level language to a h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calling Convention
In computer science, a calling convention is an implementation-level (low-level) scheme for how subroutines or functions receive parameters from their caller and how they return a result. When some code calls a function, design choices have been taken for where and how parameters are passed to that function, and where and how results are returned from that function, with these transfers typically done via certain registers or within certain structures within the call stack. There are design choices for how the tasks of preparing for a function call and restoring the environment after the function call are divided between the caller and the callee. Some calling convention specifies the way every function should get called. Introduction Calling conventions are usually considered part of the Application Binary Interface ''ABI''. Calling conventions may be related to a particular programming language's evaluation strategy, but most often are not considered part of it (or vic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abstract Interpretation
In computer science, abstract interpretation is a theory of sound approximation of the semantics of computer programs, based on monotonic functions over ordered sets, especially lattices. It can be viewed as a partial execution of a computer program which gains information about its semantics (e.g., control-flow, data-flow) without performing all the calculations. Its main concrete application is formal static analysis, the automatic extraction of information about the possible executions of computer programs; such analyses have two main usages: * inside compilers, to analyse programs to decide whether certain optimizations or transformations are applicable; * for debugging or even the certification of programs against classes of bugs. Abstract interpretation was formalized by the French computer scientist working couple Patrick Cousot and Radhia Cousot in the late 1970s. Intuition This section illustrates abstract interpretation by means of real-world, non-computing example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alan Mycroft
Alan Mycroft is a professor at the Computer Laboratory, University of Cambridge and a Fellow of Robinson College, Cambridge, where he is also director of studies for computer science. Education Mycroft read mathematics at Cambridge then moved to Edinburgh where he completed his Doctor of Philosophy degree with a thesis on ''Abstract interpretation and optimising transformations for applicative programs'' supervised by Rod Burstall and Robin Milner. Research Mycroft's research interests are in programming languages, software engineering and algorithms. With Arthur Norman (computer scientist), Arthur Norman, he co-created the Norcroft C compiler. He is also a named trustee of the Raspberry Pi Foundation, a charitable organisation whose single-board computer is intended to stimulate the teaching of basic computer science in schools. Personal life Mycroft has four children. References Living people British computer scientists Fellows of Robinson College, Cambridge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domain Theory
Domain theory is a branch of mathematics that studies special kinds of partially ordered sets (posets) commonly called domains. Consequently, domain theory can be considered as a branch of order theory. The field has major applications in computer science, where it is used to specify denotational semantics, especially for functional programming languages. Domain theory formalizes the intuitive ideas of approximation and convergence in a very general way and is closely related to topology. Motivation and intuition The primary motivation for the study of domains, which was initiated by Dana Scott in the late 1960s, was the search for a denotational semantics of the lambda calculus. In this formalism, one considers "functions" specified by certain terms in the language. In a purely syntactic way, one can go from simple functions to functions that take other functions as their input arguments. Using again just the syntactic transformations available in this formalism, one can obtain s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glasgow Haskell Compiler
The Glasgow Haskell Compiler (GHC) is an open-source native code compiler for the functional programming language Haskell. It provides a cross-platform environment for the writing and testing of Haskell code and it supports numerous extensions, libraries, and optimisations that streamline the process of generating and executing code. GHC is the most commonly used Haskell compiler. The lead developers are Simon Peyton Jones and Simon Marlow. History GHC originally started in 1989 as a prototype, written in LML (Lazy ML) by Kevin Hammond at the University of Glasgow. Later that year, the prototype was completely rewritten in Haskell, except for its parser, by Cordelia Hall, Will Partain, and Simon Peyton Jones. Its first beta release was on 1 April 1991 and subsequent releases added a strictness analyzer as well as language extensions such as monadic I/O, mutable arrays, unboxed data types, concurrent and parallel programming models (such as software transactional memory and dat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demand Analysis
In economics, demand is the quantity of a good that consumers are willing and able to purchase at various prices during a given time. The relationship between price and quantity demand is also called the demand curve. Demand for a specific item is a function of an item's perceived necessity, price, perceived quality, convenience, available alternatives, purchasers' disposable income and tastes, and many other options. Factors influencing demand Innumerable factors and circumstances affect a consumer's willingness or to buy a good. Some of the common factors are: The price of the commodity: The basic demand relationship is between potential prices of a good and the quantities that would be purchased at those prices. Generally, the relationship is negative, meaning that an increase in price will induce a decrease in the quantity demanded. This negative relationship is embodied in the downward slope of the consumer demand curve. The assumption of a negative relationship is reason ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philip Wadler
Philip Lee Wadler (born April 8, 1956) is an American computer scientist known for his contributions to programming language design and type theory. He is the chair of Theoretical Computer Science at the Laboratory for Foundations of Computer Science at School of Informatics, University of Edinburgh. He has contributed to the theory behind functional programming and the use of monads in functional programming, the design of the purely functional language Haskell, and the XQuery declarative query language. In 1984, he created the Orwell programming language. Wadler was involved in adding generic types to Java 5.0. He is also author of the paper ''Theorems for free!'' that gave rise to much research on functional language optimization (see also Parametricity). Education Wadler received a Bachelor of Science degree in mathematics from Stanford University in 1977, and a Master of Science degree in Computer Science from Carnegie Mellon University in 1979. He completed his Doctor of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
