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M-expression
In computer programming, M-expressions (or meta-expressions) were an early proposed syntax for the Lisp programming language, inspired by contemporary languages such as Fortran and ALGOL. The notation was never implemented into the language and, as such, it was never finalized. Compared to S-expressions, M-expressions introduce function notation, infix operators (including a operator), and shorthands for and into the language. Background John McCarthy published the first paper on Lisp in 1960 while a research fellow at the Massachusetts Institute of Technology. In it he described a language of symbolic expressions (S-expressions) that could represent complex structures as lists. Then he defined a set of primitive operations on the S-expressions, and a language of meta-expressions (M-expressions) that could be used to define more complex operations. Finally, he showed how the meta-language itself could be represented with S-expressions, resulting in a system that was potent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lisp (programming Language)
Lisp (historically LISP) is a family of programming languages with a long history and a distinctive, fully parenthesized prefix notation. Originally specified in 1960, Lisp is the second-oldest high-level programming language still in common use, after Fortran. Lisp has changed since its early days, and many dialects have existed over its history. Today, the best-known general-purpose Lisp dialects are Common Lisp, Scheme, Racket and Clojure. Lisp was originally created as a practical mathematical notation for computer programs, influenced by (though not originally derived from) the notation of Alonzo Church's lambda calculus. It quickly became a favored programming language for artificial intelligence (AI) research. As one of the earliest programming languages, Lisp pioneered many ideas in computer science, including tree data structures, automatic storage management, dynamic typing, conditionals, higher-order functions, recursion, the self-hosting compiler, and the read†... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-expression
In computer programming, an S-expression (or symbolic expression, abbreviated as sexpr or sexp) is an expression in a like-named notation for nested list (tree-structured) data. S-expressions were invented for and popularized by the programming language Lisp, which uses them for source code as well as data. In the usual parenthesized syntax of Lisp, an S-expression is classically definedJohn McCarthy (1960/2006)Recursive functions of symbolic expressions. Originally published in Communications of the ACM. as # an atom of the form ''x'', or # an expression of the form (''x'' . ''y'') where ''x'' and ''y'' are S-expressions. This definition reflects LISP's representation of a list as a series of "cells", each one an ordered pair. In plain lists, ''y'' points to the next cell (if any), thus forming a list. The recursive clause of the definition means that both this representation and the S-expression notation can represent any binary tree. However, the representation can in princi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MLisp
:''"MLisp" is also another name for Mocklisp, a stripped-down version of Lisp used as an extension language in Gosling Emacs.'' MLISP is a variant of Lisp with an Algol-like syntax based on M-Expressions, which were the function syntax in the original description of Lisp by John McCarthy. McCarthy's M-expressions were never implemented in an exact form. MLISP was first implemented for the IBM 360 by Horace Enea and then reimplemented for the PDP 10 by David Canfield Smith. This second implementation also supported a special kind of lambdas (" FEXPR"), which do not evaluate their arguments. As in Lisp-1 or Scheme, there was a single namespace for variables and functions. While MLISP was just a preprocessor with an alternative, more reader-friendly syntax for Lisp, the descendant MLISP 2 introduced new concepts: * interactive interpretation of programs instead of compilation * extensibility with a syntax description language (see hygienic macros) * pattern matching * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolfram Language
The Wolfram Language ( ) is a general multi-paradigm programming language developed by Wolfram Research. It emphasizes symbolic computation, functional programming, and rule-based programming and can employ arbitrary structures and data. It is the programming language of the mathematical symbolic computation program Mathematica. History The Wolfram Language was a part of the initial version of Mathematica in 1988. Symbolic aspects of the engine make it a computer algebra system. The language can perform integration, differentiation, matrix manipulations, and solve differential equations using a set of rules. Also, the initial version introduced the notebook model and the ability to embed sound and images, according to Theodore Gray's patent. Wolfram also added features for more complex tasks, such as 3D modeling. A name was finally adopted for the language in 2013, as Wolfram Research decided to make a version of the language engine free for Raspberry Pi users, and they need ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pattern Matching
In computer science, pattern matching is the act of checking a given sequence of tokens for the presence of the constituents of some pattern. In contrast to pattern recognition, the match usually has to be exact: "either it will or will not be a match." The patterns generally have the form of either sequences or tree structures. Uses of pattern matching include outputting the locations (if any) of a pattern within a token sequence, to output some component of the matched pattern, and to substitute the matching pattern with some other token sequence (i.e., search and replace). Sequence patterns (e.g., a text string) are often described using regular expressions and matched using techniques such as backtracking. Tree patterns are used in some programming languages as a general tool to process data based on its structure, e.g. C#, F#, Haskell, ML, Python, Ruby, Rust, Scala, Swift and the symbolic mathematics language Mathematica have special syntax for expressing tree patt ... [...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] |
Scheme Requests For Implementation
Scheme Requests for Implementation (SRFI) is an effort to coordinate libraries and extensions of standard Scheme programming language, necessitated by Scheme's minimalist design, and particularly the lack of a standard library before Scheme R6RS. SRFI is supported by many Scheme implementations. As such, it is an informal standard. History At the Scheme Workshop held in Baltimore, Maryland, on September 26, 1998, the attendees considered several proposals for standardized feature sets to include in Scheme implementations. Alan Bawden proposed that there be a repository for library proposals. Shriram Krishnamurthi volunteered to host the library, and Dave Mason and Mike Sperber joined him as initial editors and coordinators of the library process. The term ''Request for Implementation'', a play on the Internet ''Request for Comments A Request for Comments (RFC) is a publication in a series from the principal technical development and standards-setting bodies for the Internet, mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Off-side Rule
A computer programming language is said to adhere to the off-side rule of syntax if blocks in that language are expressed by their indentation. The term was coined by Peter Landin, possibly as a pun on the offside rule in association football. This is contrasted with free-form languages, notably curly-bracket programming languages, where indentation has no computational meaning and indent style is only a matter of coding conventions and formatting. Definition Peter Landin, in his 1966 article " The Next 700 Programming Languages", defined the off-side rule thus: "Any non-whitespace token to the left of the first such token on the previous line is taken to be the start of a new declaration." Code examples The following is an example of indentation blocks in Python. The colons are part of the Python language syntax for readability; they are not needed to implement the off-side rule. In Python, the rule is taken to define the boundaries of statements rather than declarations. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Armed Bear Common Lisp
Common Lisp (CL) is a dialect of the Lisp programming language, published in ANSI standard document ''ANSI INCITS 226-1994 (S20018)'' (formerly ''X3.226-1994 (R1999)''). The Common Lisp HyperSpec, a hyperlinked HTML version, has been derived from the ANSI Common Lisp standard. The Common Lisp language was developed as a standardized and improved successor of Maclisp. By the early 1980s several groups were already at work on diverse successors to MacLisp: Lisp Machine Lisp (aka ZetaLisp), Spice Lisp, NIL and S-1 Lisp. Common Lisp sought to unify, standardise, and extend the features of these MacLisp dialects. Common Lisp is not an implementation, but rather a language specification. Several implementations of the Common Lisp standard are available, including free and open-source software and proprietary products. Common Lisp is a general-purpose, multi-paradigm programming language. It supports a combination of procedural, functional, and object-oriented programming paradigms. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CGOL
CGOL (pronounced ''"see goll"'') is an alternative syntax featuring an extensible algebraic notation for the Lisp programming language. It was designed for MACLISP by Vaughan Pratt and subsequently ported to Common Lisp. The notation of CGOL is a traditional infix notation, in the style of ALGOL, rather than Lisp's traditional, uniformly-parenthesized prefix notation syntax. The CGOL parser is based on Pratt's design for top-down operator precedence parsing, sometimes informally referred to as a " Pratt parser". Semantically, CGOL is essentially just Common Lisp, with some additional reader and printer support. CGOL may be regarded as a more successful incarnation of some of the essential ideas behind the earlier LISP 2 project. Lisp 2 was a successor to LISP 1.5 that aimed to provide ALGOL syntax. LISP 2 was abandoned, whereas it is possible to use the CGOL codebase today. This is because unlike LISP 2, CGOL is implemented as portable functions and macros written in Lisp, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
APL (programming Language)
APL (named after the book ''A Programming Language'') is a programming language developed in the 1960s by Kenneth E. Iverson. Its central datatype is the Array data type#Multi-dimensional arrays, multidimensional array. It uses a large range of APL syntax and symbols, special graphic symbols to represent most functions and operators, leading to very concise code. It has been an important influence on the development of concept modeling, spreadsheets, functional programming, and computer math packages. It has also inspired several other programming languages. History Mathematical notation A mathematical notation for manipulating arrays was developed by Kenneth E. Iverson, starting in 1957 at Harvard University. In 1960, he began work for IBM where he developed this notation with Adin Falkoff and published it in his book ''A Programming Language'' in 1962. The preface states its premise: This notation was used inside IBM for short research reports on computer systems, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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