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Regex
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. Regul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of Regular Expression Engines
This is a comparison of regular expression engines. Libraries Languages {, class="wikitable sortable" style="width: auto; table-layout: fixed;" , + List of languages and frameworks including regular expression support , - ! Language ! Official website ! Software license ! Remarks , - ! , ActionScript 3 ActionScript Technology Center, , style="text-align: left;" , , - ! , APL (APLX, Dyalog, GNU) APL Wiki, , style="text-align: left;" , ⎕SS (PCRE), ⎕R/⎕S (PCRE), ⎕SS (PCRE2), respectively , - ! , C++11 ( C++) C++ standards website, , style="text-align: left;" , Since ISO14822:2011(e), similar to ECMAScript on defaul(Grammar Description), - ! , D D, , style="text-align: left;" , , - ! , Elixir elixir-lang.org, style="text-align: center;" {{free, Apache 2.0 , style="text-align: left;" , Standard library includes PCRE-baseRegex module The matching algorithms of the library are based on the PCRE library, but not all of the PCRE library is inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ken Thompson
Kenneth Lane Thompson (born February 4, 1943) is an American pioneer of computer science. Thompson worked at Bell Labs for most of his career where he designed and implemented the original Unix operating system. He also invented the B (programming language), B programming language, the direct predecessor to the C (programming language), C language, and was one of the creators and early developers of the Plan 9 from Bell Labs, Plan 9 operating system. Since 2006, Thompson has worked at Google, where he co-developed the Go (programming language), Go language. A recipient of the Turing award, he is considered one of the greatest computer programmers of all time. Other notable contributions included his work on regular expressions and early computer text editors QED (text editor), QED and ed (text editor), ed, the definition of the UTF-8 encoding, and his work on computer chess that included the creation of endgame tablebases and the chess machine Belle (chess machine), Belle. He won ... [...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] |
String-searching Algorithm
A string-searching algorithm, sometimes called string-matching algorithm, is an algorithm that searches a body of text for portions that match by pattern. A basic example of string searching is when the pattern and the searched text are arrays of elements of an alphabet (finite set) Σ. Σ may be a human language alphabet, for example, the letters ''A'' through ''Z'' and other applications may use a ''binary alphabet'' (Σ = ) or a ''DNA alphabet'' (Σ = ) in bioinformatics. In practice, the method of feasible string-search algorithm may be affected by the string encoding. In particular, if a variable-width encoding is in use, then it may be slower to find the ''N''th character, perhaps requiring time proportional to ''N''. This may significantly slow some search algorithms. One of many possible solutions is to search for the sequence of code units instead, but doing so may produce false matches unless the encoding is specifically designed to avoid it. Overview The most basic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SNOBOL
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 inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antony08
Antony may refer to: * Antony (name), a masculine name Films * Antony (2018 film), an Indian Tamil-language action drama film * Antony (2023 film), an Indian Malayalam-language action drama film Persons * Antony (footballer, born 2000) (Antony Matheus dos Santos), Brazilian footballer who plays for Real Betis, on loan from Manchester United * Antony (the former name of Anohni), the leader of the rock band Antony and the Johnsons * Antony (Khrapovitsky), bishop of the Russian Orthodox Church * Antony (footballer, born 2001) (Antony Alves Santos), Brazilian footballer who plays for Portland Timbers Places and structures * Antony, Belarus, a village in the Grodno Region of Belarus * Antony, Cornwall, a village in Cornwall, United Kingdom ** Antony House, Cornwall, England * Arrondissement of Antony, in the Hauts-de-Seine ''département'' of France ** Antony, Hauts-de-Seine Antony () is a Communes of France, commune in the southern suburbs of Paris, France, from the Kilometr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lexical Analysis
Lexical tokenization is conversion of a text into (semantically or syntactically) meaningful ''lexical tokens'' belonging to categories defined by a "lexer" program. In case of a natural language, those categories include nouns, verbs, adjectives, punctuations etc. In case of a programming language, the categories include identifiers, operators, grouping symbols, data types and language keywords. Lexical tokenization is related to the type of tokenization used in large language models (LLMs) but with two differences. First, lexical tokenization is usually based on a lexical grammar, whereas LLM tokenizers are usually probability-based. Second, LLM tokenizers perform a second step that converts the tokens into numerical values. Rule-based programs A rule-based program, performing lexical tokenization, is called ''tokenizer'', or ''scanner'', although ''scanner'' is also a term for the first stage of a lexer. A lexer forms the first phase of a compiler frontend in processing. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O'Reilly Media
O'Reilly Media, Inc. (formerly O'Reilly & Associates) is an American learning company established by Tim O'Reilly that provides technical and professional skills development courses via an online learning platform. O'Reilly also publishes books about programming and other technical content. Its distinctive brand features a woodcut of an animal on many of its book covers. The company was known as a popular tech conference organizer for more than 20 years before closing the live conferences arm of its business. Company Early days The company began in 1978 as a private consulting firm doing technical writing, based in the Cambridge, Massachusetts area. In 1984, it began to retain publishing rights on manuals created for Unix vendors. A few 70-page "Nutshell Handbooks" were well-received, but the focus remained on the consulting business until 1988. After a conference displaying O'Reilly's preliminary Xlib manuals attracted significant attention, the company began increas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Text File
A text file (sometimes spelled textfile; an old alternative name is flat file) is a kind of computer file that is structured as a sequence of lines of electronic text. A text file exists stored as data within a computer file system. In operating systems such as CP/M, where the operating system does not keep track of the file size in bytes, the end of a text file is denoted by placing one or more special characters, known as an end-of-file (EOF) marker, as padding after the last line in a text file. In modern operating systems such as DOS, Microsoft Windows and Unix-like systems, text files do not contain any special EOF character, because file systems on those operating systems keep track of the file size in bytes. Some operating systems, such as Multics, Unix-like systems, CP/M, DOS, the classic Mac OS, and Windows, store text files as a sequence of bytes, with an end-of-line delimiter at the end of each line. Other operating systems, such as OpenVMS and OS/360 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QED (text Editor)
QED is a line-oriented computer text editor that was developed by Butler Lampson and L. Peter Deutsch for the Berkeley Timesharing System running on the SDS 940. It was implemented by L. Peter Deutsch and Dana Angluin between 1965 and 1966. QED (for "quick editor") addressed teleprinter usage, but systems "for CRT displays erenot considered, since many of their design considerations erequite different." Later implementations Ken Thompson later wrote a version for CTSS; this version was notable for introducing regular expressions. Thompson rewrote QED in BCPL for Multics. The Multics version was ported to the GE-600 system used at Bell Labs in the late 1960s under GECOS and later GCOS after Honeywell took over GE's computer business. The GECOS-GCOS port used I/O routines written by A. W. Winklehoff. Dennis Ritchie, Ken Thompson and Brian Kernighan wrote the QED manuals used at Bell Labs. Given that the authors were the primary developers of the Unix operating system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McCulloch-Pitts Neuron
An artificial neuron is a mathematical function conceived as a model of a biological neuron in a neural network. The artificial neuron is the elementary unit of an ''artificial neural network''. The design of the artificial neuron was inspired by biological neural circuitry. Its inputs are analogous to excitatory postsynaptic potentials and inhibitory postsynaptic potentials at neural dendrites, or . Its weights are analogous to synaptic weights, and its output is analogous to a neuron's action potential which is transmitted along its axon. Usually, each input is separately weighted, and the sum is often added to a term known as a ''bias'' (loosely corresponding to the threshold potential), before being passed through a nonlinear function known as an activation function. Depending on the task, these functions could have a sigmoid shape (e.g. for binary classification), but they may also take the form of other nonlinear functions, piecewise linear functions, or step functi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perceptron
In machine learning, the perceptron is an algorithm for supervised classification, supervised learning of binary classification, binary classifiers. A binary classifier is a function that can decide whether or not an input, represented by a vector of numbers, belongs to some specific class. It is a type of linear classifier, i.e. a classification algorithm that makes its predictions based on a linear predictor function combining a set of Weighting, weights with the feature vector. History The artificial neuron network was invented in 1943 by Warren McCulloch and Walter Pitts in ''A Logical Calculus of the Ideas Immanent in Nervous Activity, A logical calculus of the ideas immanent in nervous activity''. In 1957, Frank Rosenblatt was at the Cornell Aeronautical Laboratory. He simulated the perceptron on an IBM 704. Later, he obtained funding by the Information Systems Branch of the United States Office of Naval Research and the Rome Air Development Center, to build a custom- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
