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Spaghetti Stack
In computer science, an in-tree or parent pointer tree is an -ary tree data structure in which each node has a pointer to its parent node, but no pointers to child nodes. When used to implement a set of stacks, the structure is called a spaghetti stack, cactus stack or sahuaro stack (after the sahuaro, a kind of cactus). Parent pointer trees are also used as disjoint-set data structures. The structure can be regarded as a set of singly linked lists that share part of their structure, in particular, their tails. From any node, one can traverse to ancestors of the node, but not to any other node. Use in compilers A compiler for a language such as C creates a spaghetti stack as it opens and closes symbol tables representing block scopes. When a new block scope is opened, a symbol table is pushed onto a stack. When the closing curly brace is encountered, the scope is closed and the symbol table is popped. But that symbol table is remembered, rather than destroyed. And of course it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuation
In computer science, a continuation is an abstract representation of the control state of a computer program. A continuation implements ( reifies) the program control state, i.e. the continuation is a data structure that represents the computational process at a given point in the process's execution; the created data structure can be accessed by the programming language, instead of being hidden in the runtime environment. Continuations are useful for encoding other control mechanisms in programming languages such as exceptions, generators, coroutines, and so on. The "current continuation" or "continuation of the computation step" is the continuation that, from the perspective of running code, would be derived from the current point in a program's execution. The term ''continuations'' can also be used to refer to first-class continuations, which are constructs that give a programming language the ability to save the execution state at any point and return to that point at a lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burroughs Large Systems
The Burroughs Large Systems Group produced a family of large 48-bit mainframes using stack machine instruction sets with dense syllables.E.g., 12-bit syllables for B5000, 8-bit syllables for B6500 The first machine in the family was the B5000 in 1961. It was optimized for compiling ALGOL 60 programs extremely well, using single-pass compilers. It evolved into the B5500. Subsequent major redesigns include the B6500/B6700 line and its successors, as well as the separate B8500 line. In the 1970s, the Burroughs Corporation was organized into three divisions with very different product line architectures for high-end, mid-range, and entry-level business computer systems. Each division's product line grew from a different concept for how to optimize a computer's instruction set for particular programming languages. "Burroughs Large Systems" referred to all of these large-system product lines together, in contrast to the COBOL-optimized Medium Systems (B2000, B3000, and B4000) or the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mainframe Computers
A mainframe computer, informally called a mainframe or big iron, is a computer used primarily by large organizations for critical applications like bulk data processing for tasks such as censuses, industry and consumer statistics, enterprise resource planning, and large-scale transaction processing. A mainframe computer is large but not as large as a supercomputer and has more processing power than some other classes of computers, such as minicomputers, servers, workstations, and personal computers. Most large-scale computer-system architectures were established in the 1960s, but they continue to evolve. Mainframe computers are often used as servers. The term ''mainframe'' was derived from the large cabinet, called a ''main frame'', that housed the central processing unit and main memory of early computers. Later, the term ''mainframe'' was used to distinguish high-end commercial computers from less powerful machines. Design Modern mainframe design is characterized less b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cilk
Cilk, Cilk++, Cilk Plus and OpenCilk are general-purpose programming languages designed for multithreaded parallel computing. They are based on the C and C++ programming languages, which they extend with constructs to express parallel loops and the fork–join idiom. Originally developed in the 1990s at the Massachusetts Institute of Technology (MIT) in the group of Charles E. Leiserson, Cilk was later commercialized as Cilk++ by a spinoff company, Cilk Arts. That company was subsequently acquired by Intel, which increased compatibility with existing C and C++ code, calling the result Cilk Plus. After Intel stopped supporting Cilk Plus in 2017, MIT is again developing Cilk in the form of OpenCilk. History MIT Cilk The Cilk programming language grew out of three separate projects at the MIT Laboratory for Computer Science: * Theoretical work on scheduling multi-threaded applications. * StarTech – a parallel chess program built to run on the Thinking Machines Corporation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Felix (programming Language)
Felix may refer to: * Felix (name), people and fictional characters with the name Places * Arabia Felix is the ancient Latin name of Yemen * Felix, Spain, a municipality of the province Almería, in the autonomous community of Andalusia, Spain * St. Felix, Prince Edward Island, a rural community in Prince County, Prince Edward Island, Canada. * Felix, Ontario, an unincorporated place and railway point in Northeastern Ontario, Canada * St. Felix, South Tyrol, a village in South Tyrol, in northern Italy. * Felix, California, an unincorporated community in Calaveras County Music * Felix (band), a British band * Felix (musician), British DJ * Félix Award, a Quebec music award named after Félix Leclerc Business * Felix (pet food), a brand of cat food sold in most European countries * AB Felix, a Swedish food company * Felix Bus Services of Derbyshire, England * Felix Airways, an airline based in Yemen Science and technology * Apache Felix, an open source OSGi framewo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard ML Of New Jersey
Standard ML of New Jersey (SML/NJ; Standard Meta-Language of New Jersey) is a free and open-source compiler and programming environment for the Standard ML programming language. Aside from its runtime system, which is written in C, SML/NJ is written in Standard ML. It was originally developed jointly by Bell Laboratories and Princeton University. Its name is a reference both to the American state of New Jersey in which Princeton and Bell Labs are located and to Standard Oil of New Jersey, the famous oil monopoly of the early 20th century. Features SML/NJ extends the SML'97 Basis Library with several additional top-level structures: * System info – the SysInfo structure provides information about the runtime system, such as the operating system kind, type and version and whether or not the machine supports multiprocessing. * Weak pointers – the Weak structure provides support for weak pointers. * Lazy suspensions – the Susp structure implements the suspensions necessar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scheme (programming Language)
Scheme is a dialect of the Lisp family of programming languages. Scheme was created during the 1970s at the MIT AI Lab and released by its developers, Guy L. Steele and Gerald Jay Sussman, via a series of memos now known as the Lambda Papers. It was the first dialect of Lisp to choose lexical scope and the first to require implementations to perform tail-call optimization, giving stronger support for functional programming and associated techniques such as recursive algorithms. It was also one of the first programming languages to support first-class continuations. It had a significant influence on the effort that led to the development of Common Lisp.Common LISP: The Language, 2nd Ed., Guy L. Steele Jr. Digital Press; 1981. . "Common Lisp is a new dialect of Lisp, a successor to MacLisp, influenced strongly by ZetaLisp and to some extent by Scheme and InterLisp." The Scheme language is standardized in the official IEEE standard1178-1990 (Reaff 2008) IEEE Standard for the S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Closure (computer Science)
In programming languages, a closure, also lexical closure or function closure, is a technique for implementing lexically scoped name binding in a language with first-class functions. Operationally, a closure is a record storing a function together with an environment. The environment is a mapping associating each free variable of the function (variables that are used locally, but defined in an enclosing scope) with the value or reference to which the name was bound when the closure was created. Unlike a plain function, a closure allows the function to access those ''captured variables'' through the closure's copies of their values or references, even when the function is invoked outside their scope. History and etymology The concept of closures was developed in the 1960s for the mechanical evaluation of expressions in the λ-calculus and was first fully implemented in 1970 as a language feature in the PAL programming language to support lexically scoped first-class functions. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Funarg Problem
In computer science, the funarg problem ''(function argument problem)'' refers to the difficulty in implementing first-class functions (functions as first-class objects) in programming language implementations so as to use stack-based memory allocation of the functions. The difficulty only arises if the body of a nested function refers directly (i.e., not by argument passing) to identifiers defined in the environment in which the function is defined, but not in the environment of the function call. A standard resolution is either to forbid such references or to create closures. There are two subtly different versions of the funarg problem. The upwards funarg problem arises from returning (or otherwise transmitting "upwards") a function from a function call. The downwards funarg problem arises from passing a function as a parameter to another function call. Upwards funarg problem When one function calls another during a typical program's execution, the local state of the caller (in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garbage Collection (computer Science)
In computer science, garbage collection (GC) is a form of automatic memory management. The ''garbage collector'' attempts to reclaim memory which was allocated by the program, but is no longer referenced; such memory is called '' garbage''. Garbage collection was invented by American computer scientist John McCarthy around 1959 to simplify manual memory management in Lisp. Garbage collection relieves the programmer from doing manual memory management, where the programmer specifies what objects to de-allocate and return to the memory system and when to do so. Other, similar techniques include stack allocation, region inference, and memory ownership, and combinations thereof. Garbage collection may take a significant proportion of a program's total processing time, and affect performance as a result. Resources other than memory, such as network sockets, database handles, windows, file descriptors, and device descriptors, are not typically handled by garbage collection, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
