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Sigil (computer Programming)
In computer programming, a sigil () is a symbol affixed to a variable name, showing the variable's datatype or scope, usually a prefix, as in $foo, where $ is the sigil. '' Sigil'', from the Latin '' sigillum'', meaning a "little sign", means ''a sign or image supposedly having magical power''. Sigils can be used to separate and demarcate namespaces that possess different properties or behaviors. Historical context The use of sigils was popularized by the BASIC programming language. The best known example of a sigil in BASIC is the dollar sign ("$") appended to the names of all strings. Many BASIC dialects use other sigils (like "%") to denote integers and floating-point numbers and their precision, and sometimes other types as well. Larry Wall adopted shell scripting's use of sigils for his Perl programming language. In Perl, the sigils do not specify fine-grained data types like strings and integers, but the more general categories of scalars (using a prefixed "$"), arra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Programming
Computer programming or coding is the composition of sequences of instructions, called computer program, programs, that computers can follow to perform tasks. It involves designing and implementing algorithms, step-by-step specifications of procedures, by writing source code, code in one or more programming languages. Programmers typically use high-level programming languages that are more easily intelligible to humans than machine code, which is directly executed by the central processing unit. Proficient programming usually requires expertise in several different subjects, including knowledge of the Domain (software engineering), application domain, details of programming languages and generic code library (computing), libraries, specialized algorithms, and Logic#Formal logic, formal logic. Auxiliary tasks accompanying and related to programming include Requirements analysis, analyzing requirements, Software testing, testing, debugging (investigating and fixing problems), imple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalar (computing)
Scalar processors are a class of computer processors that process only one data item at a time. Typical data items include integers and floating point numbers. Classification A scalar processor is classified as a single instruction, single data ( SISD) processor in Flynn's taxonomy. The Intel 486 is an example of a scalar processor. It is to be contrasted with a vector processor where a single instruction operates simultaneously on multiple data items (and thus is referred to as a single instruction, multiple data (SIMD) processor). The difference is analogous to the difference between scalar and vector arithmetic. The term ''scalar'' in computing dates to the 1970 and 1980s when vector processors were first introduced. It was originally used to distinguish the older designs from the new vector processors. Superscalar processor A superscalar processor (such as the Intel P5) may execute more than one instruction during a clock cycle by simultaneously dispatching multiple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compiler
In computing, a compiler is a computer program that Translator (computing), 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 lower level language, 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 Central processing unit, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class (computer Programming)
In object-oriented programming, a class defines the shared aspects of objects created from the class. The capabilities of a class differ between programming languages, but generally the shared aspects consist of state ( variables) and behavior ( methods) that are each either associated with a particular object or with all objects of that class. Object state can differ between each instance of the class whereas the class state is shared by all of them. The object methods include access to the object state (via an implicit or explicit parameter that references the object) whereas class methods do not. If the language supports inheritance, a class can be defined based on another class with all of its state and behavior plus additional state and behavior that further specializes the class. The specialized class is a ''sub-class'', and the class it is based on is its ''superclass''. Attributes Object lifecycle As an instance of a class, an object is constructed from a class via '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
INTERCAL
The Compiler Language With No Pronounceable Acronym (INTERCAL) is an esoteric programming language that was created as a parody by Don Woods (programmer), Don Woods and , two Princeton University students, in 1972. It satirizes aspects of the various programming languages at the time, as well as the proliferation of proposed language constructs and notations in the 1960s. There are two maintained implementations of INTERCAL dialects: C-INTERCAL (created in 1990), maintained by Eric S. Raymond and Alex Smith, and CLC-INTERCAL, maintained by Claudio Calvelli. History According to the original manual by the authors, The original Princeton implementation used punched cards and the EBCDIC character set. To allow INTERCAL to run on computers using ASCII, substitutions for two characters had to be made: $ substituted for ¢ as the ''mingle'' operator, "represent[ing] the increasing cost of software in relation to hardware", and ? was substituted for ⊻ as the unary exclusive-or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esoteric Programming Language
An esoteric programming language (sometimes shortened to esolang) is a programming language designed to test the boundaries of computer programming language design, as a proof of concept, as software art, as a hacking interface to another language (particularly functional programming or procedural programming languages), or as a joke. The use of the word ''wiktionary:esoteric, esoteric'' distinguishes them from languages that working developers use to write software. The creators of most esolangs do not intend them to be used for mainstream programming, although some esoteric features, such as live Data and information visualization, visualization of code, have inspired practical applications in the arts. Such languages are often popular among Hacker culture, hackers and hobbyists. Usability is rarely a goal for designers of esoteric programming languages; often their design leads to quite the opposite. Their usual aim is to remove or replace conventional language features while sti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elixir (programming Language)
Elixir is a functional, concurrent, high-level general-purpose programming language that runs on the BEAM virtual machine, which is also used to implement the Erlang programming language. Elixir builds on top of Erlang and shares the same abstractions for building distributed, fault-tolerant applications. Elixir also provides tooling and an extensible design. The latter is supported by compile-time metaprogramming with macros and polymorphism via protocols. The community organizes yearly events in the United States, Europe, and Japan, as well as minor local events and conferences. History José Valim created the Elixir programming language as a research and development project at Plataformatec. His goals were to enable higher extensibility and productivity in the Erlang VM while maintaining compatibility with Erlang's ecosystem. Elixir is aimed at large-scale sites and apps. It uses features of Ruby, Erlang, and Clojure to develop a high-concurrency and low-latency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CycL
CycL in computer science and artificial intelligence, is an ontology language used by Douglas Lenat's Cyc artificial intelligence project. Ramanathan V. Guha was instrumental in designing early versions of the language. A close CycL variant exists named ''MELD''. The original version of CycL was a frame language, but the modern version is not. Rather, it is a declarative language based on classical first-order logic, with extensions for modal logic operators and higher-order logic quantification. CycL is used to represent the knowledge stored in the Cyc Knowledge Base, available from Cycorp. The source code written in CycL released with the OpenCyc system is licensed as free and open-source software, to increase its usefulness in supporting the semantic web. Basic ideas The basic ideas of CycL include: * Naming the constants used to refer to information for represented concepts. * Grouping the constants together in a generalization—specialization hierarchy, usually call ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earmuff Convention
Common Lisp (CL) is a dialect of the Lisp programming language, published in American National Standards Institute (ANSI) standard document ''ANSI INCITS 226-1994 (S2018)'' (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, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CLIPS
CLIPS (C Language Integrated Production System) is a public-domain software tool for building expert systems. The syntax and name were inspired by Charles Forgy's OPS5. The first versions of CLIPS were developed starting in 1985 at the NASA Johnson Space Center (as an alternative for existing system ART*Inference) until 1996, when the development group's responsibilities ceased to focus on expert system technology. The original name of the project was ''NASA's AI Language'' (NAIL). As of 2005, CLIPS was probably the most widely used expert system tool. CLIPS is written in C, extensions can be written in C, and CLIPS can be called from C. Its syntax resembles that of the programming language Lisp. CLIPS incorporates a complete object-oriented programming language for writing expert systems. COOL combines the programming paradigms of procedural, object oriented, and logic programming (automated theorem proving) languages. Facts and rules CLIPS uses forward chaining. Like othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caret
Caret () is the name used familiarly for the character provided on most QWERTY keyboards by typing . The symbol has a variety of uses in programming and mathematics. The name "caret" arose from its visual similarity to the original proofreader's caret, , a mark used in proofreading to indicate where a punctuation mark, word, or phrase should be inserted into a document. The ASCII standard (X3.64.1977) calls it a "circumflex"; the Unicode standard calls it a "circumflex accent", although it is no longer practicable for that purpose. History Typewriters On typewriters designed for languages that routinely use diacritics (accent marks), there are two possible ways to type these: keys can be dedicated to precomposed characters (with the diacritic included); alternatively a dead key mechanism can be provided. With the latter, a mark is made when a dead key is typed but, unlike normal keys, the paper carriage does not move on and thus the next letter to be typed is printed under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
