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SNOBOL4
SNOBOL ("StriNg Oriented and symBOlic Language") is a series of programming languages developed between 1962 and 1967 at AT&T Bell Laboratories by David J. Farber, Ralph Griswold and Ivan P. Polonsky, culminating in SNOBOL4. It was one of a number of text-string-oriented languages developed during the 1950s and 1960s; others included COMIT and TRAC. Despite the similar name, it is entirely unlike COBOL. SNOBOL4 stands apart from most programming languages of its era by having patterns as a first-class data type, a data type whose values can be manipulated in all ways permitted to any other data type in the programming language, and by providing operators for pattern concatenation and alternation. SNOBOL4 patterns are a type of object and admit various manipulations, much like later object-oriented languages such as JavaScript whose patterns are known as regular expressions. In addition SNOBOL4 strings generated during execution can be treated as programs and either interpret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Icon (programming Language)
Icon is a very high-level programming language based on the concept of "goal-directed execution" in which an Expression (computer science), expression in code returns "success" along with a result, or a "failure", indicating that there is no valid result. The success and failure of a given expression is used to direct further processing, whereas conventional languages would typically use Boolean logic written by the programmer to achieve the same ends. Because the logic for basic control structures is often implicit in Icon, common tasks can be completed with less explicit code. Icon was designed by Ralph Griswold after leaving Bell Labs where he was a major contributor to the SNOBOL language. SNOBOL was a string-processing language with what would be considered dated syntax by the standards of the early 1970s. After moving to the University of Arizona, he further developed the underlying SNOBOL concepts in SL5, but considered the result to be a failure. This led to the significan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SPITBOL
SPITBOL (Speedy Implementation of SNOBOL) is a compiled implementation of the SNOBOL4 programming language. Originally targeted for the IBM System/360 and System/370 family of computers, it has now been ported to most major microprocessors including the SPARC. It was created by Robert Dewar and Ken Belcher, who were then at the Illinois Institute of Technology. Prior to the development of SPITBOL, SNOBOL4 was thought to be slow, memory-intensive, and impossible to compile due to its dynamic nature. While delayed binding prevents everything from being determined at compile time, SPITBOL adopts various strategies for making decisions as early as possible. Recent versions of the SPITBOL compiler are available. Since 2001 the source code for the original SPITBOL 360 compiler has been made available under the GNU General Public License. MACRO SPITBOL is an implementation of SPITBOL written in the 1970s by Robert Dewar and Anthony P. McCann. MACRO SPITBOL is coded in MINIMAL, an as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bs (programming Language)
bs is a programming language and a compiler/interpreter for modest-sized programs on UNIX systems. The bs command can be invoked either for interactive programming or with a file containing a program, optionally taking arguments, via a Unix shell, e.g., using a Shebang (Unix) #!/usr/bin/bs. An early man page states, " bs">kbd>bsis a remote descendant of Basic icand SNOBOL4, with a little C thrown in." History The bs command appears in UNIX System III Release 3.0 (1980), first released outside of Bell Labs in 1982. It was written by Dick Haight (Richard C. Haight) circa 1978, who recounts it as follows:Personal communication from Dick Haight, 10 September 2019. The Release 3.0 manual mentions bs prominently on page 9 (emphasis added): While not released outside prior to System III, the bs command was present internally in UNIX/TS 1.0 (November 1978),Personal conversation with John R. Mashey, 9 September 2019. PWB/UNIX 2.0 (June 1979), and CB UNIX editions 2.1 (Novembe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imperative Programming
In computer science, imperative programming is a programming paradigm of software that uses Statement (computer science), statements that change a program's state (computer science), state. In much the same way that the imperative mood in natural languages expresses commands, an imperative program consists of command (computing), commands for the computer to perform. Imperative programming focuses on describing ''how'' a program operates step by step (with general order of the steps being determined in source code by the placement of statements one below the other), rather than on high-level descriptions of its expected results. The term is often used in contrast to declarative programming, which focuses on ''what'' the program should accomplish without specifying all the details of ''how'' the program should achieve the result. Procedural programming Procedural programming is a type of imperative programming in which the program is built from one or more procedures (also termed s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternation (formal Language Theory)
In formal language theory and pattern matching, alternation is the union of two sets of strings, or equivalently the logical disjunction of two patterns describing sets of strings. Regular languages are closed under alternation, meaning that the alternation of two regular languages is again regular. In implementations of regular expressions, alternation is often expressed with a vertical bar connecting the expressions for the two languages whose union is to be matched, while in more theoretical studies the plus sign may instead be used for this purpose. The ability to construct finite automata for unions of two regular languages that are themselves defined by finite automata is central to the equivalence between regular languages defined by automata and by regular expressions. Other classes of languages that are closed under alternation include context-free languages and recursive languages. The vertical bar notation for alternation is used in the SNOBOL language and some other la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object-oriented Language
Object-oriented programming (OOP) is a programming paradigm based on the concept of '' objects''. Objects can contain data (called fields, attributes or properties) and have actions they can perform (called procedures or methods and implemented in code In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communicati ...). In OOP, computer programs are designed by making them out of objects that interact with one another. Many of the most widely used programming languages (such as C++, Java (programming language), Java, and Python (programming language), Python) support object-oriented programming to a greater or lesser degree, typically as part of multi-paradigm, multiple paradigms in combination with others such as imperative programming and declarative programming. Significant object-orient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JavaScript
JavaScript (), often abbreviated as JS, is a programming language and core technology of the World Wide Web, alongside HTML and CSS. Ninety-nine percent of websites use JavaScript on the client side for webpage behavior. Web browsers have a dedicated JavaScript engine that executes the client code. These engines are also utilized in some servers and a variety of apps. The most popular runtime system for non-browser usage is Node.js. JavaScript is a high-level, often just-in-time–compiled language that conforms to the ECMAScript standard. It has dynamic typing, prototype-based object-orientation, and first-class functions. It is multi-paradigm, supporting event-driven, functional, and imperative programming styles. It has application programming interfaces (APIs) for working with text, dates, regular expressions, standard data structures, and the Document Object Model (DOM). The ECMAScript standard does not include any input/output (I/O), such as netwo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regular Expression
A regular expression (shortened as regex or regexp), sometimes referred to as rational expression, is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation. Regular expression techniques are developed in theoretical computer science and formal language theory. The concept of regular expressions began in the 1950s, when the American mathematician Stephen Cole Kleene formalized the concept of a regular language. They came into common use with Unix text-processing utilities. Different syntaxes for writing regular expressions have existed since the 1980s, one being the POSIX standard and another, widely used, being the Perl syntax. Regular expressions are used in search engines, in search and replace dialogs of word processors and text editors, in text processing utilities such as sed and AWK, and in lexical analysis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eval
In some programming languages, eval , short for evaluate, is a function which evaluates a string as though it were an expression in the language, and returns a result; in others, it executes multiple lines of code as though they had been included instead of the line including the eval. The input to eval is not necessarily a string; it may be structured representation of code, such as an abstract syntax tree (like Lisp forms), or of special type such as code (as in Python). The analog for a statement is exec, which executes a string (or code in other format) as if it were a statement; in some languages, such as Python, both are present, while in other languages only one of either eval or exec is. Security risks Using eval with data from an untrusted source may introduce security vulnerabilities. For instance, assuming that the get_data() function gets data from the Internet, this Python code is insecure: session authenticated'= False data = get_data() foo = eval(data) A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humanities
Humanities are academic disciplines that study aspects of human society and culture, including Philosophy, certain fundamental questions asked by humans. During the Renaissance, the term "humanities" referred to the study of classical literature and language, as opposed to the study of religion, or "divinity". The study of the humanities was a key part of the secular curriculum in universities at the time. Today, the humanities are more frequently defined as any fields of study outside of natural sciences, social sciences, formal sciences (like mathematics), and applied sciences (or Professional development, professional training). They use methods that are primarily Critical theory, critical, speculative, or interpretative and have a significant historical element—as distinguished from the mainly Empirical method, empirical approaches of science."Humanity" 2.b, ''Oxford English Dictionary'', 3rd ed. (2003). The humanities include the academic study of philosophy, religion, histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First-class Object
In a given programming language design, a first-class citizen is an entity which supports all the operations generally available to other entities. These operations typically include being passed as an argument, returned from a function, and assigned to a variable. History The concept of first- and second-class objects was introduced by Christopher Strachey in the 1960s. He did not actually define the term strictly, but contrasted real numbers and procedures in ALGOL: First and second class objects. In ALGOL, a real number may appear in an expression or be assigned to a variable, and either of them may appear as an actual parameter in a procedure call. A procedure, on the other hand, may only appear in another procedure call either as the operator (the most common case) or as one of the actual parameters. There are no other expressions involving procedures or whose results are procedures. Thus in a sense procedures in ALGOL are second class citizens—they always have to appear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perl
Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language". Perl was developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions. Perl originally was not capitalized and the name was changed to being capitalized by the time Perl 4 was released. The latest release is Perl 5, first released in 1994. From 2000 to October 2019 a sixth version of Perl was in development; the sixth version's name was changed to Raku. Both languages continue to be developed independently by different development teams which liberally borrow ideas from each other. Perl borrows features from other programming languages including C, sh, AWK, and sed. It provides text processing facilities without the arbitrary data-length limits of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
