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Code Point
In character encoding terminology, a code point, codepoint or code position is a numerical value that maps to a specific character. Code points usually represent a single grapheme—usually a letter, digit, punctuation mark, or whitespace—but sometimes represent symbols, control characters, or formatting. The set of all possible code points within a given encoding/character set make up that encoding's ''codespace''. For example, the character encoding scheme ASCII comprises 128 code points in the range 0hex to 7Fhex, Extended ASCII comprises 256 code points in the range 0hex to FFhex, and Unicode comprises code points in the range 0hex to 10FFFFhex. The Unicode code space is divided into seventeen planes (the basic multilingual plane, and 16 supplementary planes), each with (= 216) code points. Thus the total size of the Unicode code space is 17 × = . Definition The notion of a code point is used for abstraction, to distinguish both: * the num ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Character (computing)
In computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language. Examples of characters include letters, numerical digits, common punctuation marks (such as "." or "-"), and whitespace. The concept also includes control characters, which do not correspond to visible symbols but rather to instructions to format or process the text. Examples of control characters include carriage return and tab as well as other instructions to printers or other devices that display or otherwise process text. Characters are typically combined into strings. Historically, the term ''character'' was used to denote a specific number of contiguous bits. While a character is most commonly assumed to refer to 8 bits (one byte) today, other options like the 6-bit character code were once popular, and the 5-bit Bau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Character (computing)
In computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language. Examples of characters include letters, numerical digits, common punctuation marks (such as "." or "-"), and whitespace. The concept also includes control characters, which do not correspond to visible symbols but rather to instructions to format or process the text. Examples of control characters include carriage return and tab as well as other instructions to printers or other devices that display or otherwise process text. Characters are typically combined into strings. Historically, the term ''character'' was used to denote a specific number of contiguous bits. While a character is most commonly assumed to refer to 8 bits (one byte) today, other options like the 6-bit character code were once popular, and the 5-bit Bau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Character Encoding
Character encoding is the process of assigning numbers to graphical characters, especially the written characters of human language, allowing them to be stored, transmitted, and transformed using digital computers. The numerical values that make up a character encoding are known as "code points" and collectively comprise a "code space", a "code page", or a " character map". Early character codes associated with the optical or electrical telegraph could only represent a subset of the characters used in written languages, sometimes restricted to upper case letters, numerals and some punctuation only. The low cost of digital representation of data in modern computer systems allows more elaborate character codes (such as Unicode) which represent most of the characters used in many written languages. Character encoding using internationally accepted standards permits worldwide interchange of text in electronic form. History The history of character codes illustrates the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Replacement Character
Specials is a short Unicode block of characters allocated at the very end of the Basic Multilingual Plane, at U+FFF0–FFFF. Of these 16 code points, five have been assigned since Unicode 3.0: *, marks start of annotated text *, marks start of annotating character(s) *, marks end of annotation block *, placeholder in the text for another unspecified object, for example in a compound document. * used to replace an unknown, unrecognized, or unrepresentable character * not a character. * not a character. FFFE and FFFF are not unassigned in the usual sense, but guaranteed not to be Unicode characters at all. They can be used to guess a text's encoding scheme, since any text containing these is by definition not a correctly encoded Unicode text. Unicode's character can be inserted at the beginning of a Unicode text to signal its endianness: a program reading such a text and encountering 0xFFFE would then know that it should switch the byte order for all the following characters. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Text-based (computing)
In computing, text-based user interfaces (TUI) (alternately terminal user interfaces, to reflect a dependence upon the properties of computer terminals and not just text), is a retronym describing a type of user interface (UI) common as an early form of human–computer interaction, before the advent of modern conventional graphical user interfaces (GUIs). Like GUIs, they may use the entire Electronic visual display, screen area and accept mouse (computing), mouse and other inputs. They may also use color and often structure the display using special graphical Character (computing), characters such as ┌ and ╣, referred to in Unicode as the "box drawing" set. The modern context of use is usually a terminal emulator. Types of text terminals From console application, text application's point of view, a text screen (and communications with it) can belong to one of three types (here ordered in order of decreasing accessibility): # A genuine text mode display, controlled by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combining Character
In digital typography, combining characters are characters that are intended to modify other characters. The most common combining characters in the Latin script are the combining diacritical marks (including combining accents). Unicode also contains many precomposed characters, so that in many cases it is possible to use both combining diacritics and precomposed characters, at the user's or application's choice. This leads to a requirement to perform Unicode normalization before comparing two Unicode strings and to carefully design encoding converters to correctly map all of the valid ways to represent a character in Unicode to a legacy encoding to avoid data loss. In Unicode, the main block of combining diacritics for European languages and the International Phonetic Alphabet is U+0300–U+036F. Combining diacritical marks are also present in many other blocks of Unicode characters. In Unicode, diacritics are always added after the main character (in contrast to some o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicode Consortium
The Unicode Consortium (legally Unicode, Inc.) is a 501(c)(3) non-profit organization incorporated and based in Mountain View, California. Its primary purpose is to maintain and publish the Unicode Standard which was developed with the intention of replacing existing character encoding schemes which are limited in size and scope, and are incompatible with multilingual environments. The consortium describes its overall purpose as: Unicode's success at unifying character sets has led to its widespread adoption in the internationalization and localization of software. The standard has been implemented in many technologies, including XML, the Java programming language, Swift, and modern operating systems. Voting members include computer software and hardware companies with an interest in text-processing standards, including Adobe, Apple, the Bangladesh Computer Council, Emojipedia, Facebook, Google, IBM, Microsoft, the Omani Ministry of Endowments and Religious Affairs, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latin Script
The Latin script, also known as Roman script, is an alphabetic writing system based on the letters of the classical Latin alphabet, derived from a form of the Greek alphabet which was in use in the ancient Greece, Greek city of Cumae, in southern Italy (Magna Grecia). It was adopted by the Etruscan civilization, Etruscans and subsequently by the Ancient Rome, Romans. Several Latin-script alphabets exist, which differ in graphemes, collation and phonetic values from the classical Latin alphabet. The Latin script is the basis of the International Phonetic Alphabet, and the 26 most widespread letters are the letters contained in the ISO basic Latin alphabet. Latin script is the basis for the largest number of alphabets of any writing system and is the List of writing systems by adoption, most widely adopted writing system in the world. Latin script is used as the standard method of writing for most Western and Central, and some Eastern, European languages as well as many languages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Page
In computing, a code page is a character encoding and as such it is a specific association of a set of printable characters and control characters with unique numbers. Typically each number represents the binary value in a single byte. (In some contexts these terms are used more precisely; see .) The term "code page" originated from IBM's EBCDIC-based mainframe systems, but Microsoft, SAP, and Oracle Corporation are among the vendors that use this term. The majority of vendors identify their own character sets by a name. In the case when there is a plethora of character sets (like in IBM), identifying character sets through a number is a convenient way to distinguish them. Originally, the code page numbers referred to the ''page'' numbers in the IBM standard character set manual, a condition which has not held for a long time. Vendors that use a code page system allocate their own code page number to a character encoding, even if it is better known by another name; for example, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-synchronizing Code
In coding theory, especially in telecommunications, a self-synchronizing code is a uniquely decodable code in which the symbol stream formed by a portion of one code word, or by the overlapped portion of any two adjacent code words, is not a valid code word. Put another way, a set of strings (called "code words") over an alphabet is called a self-synchronizing code if for each string obtained by concatenating two code words, the substring starting at the second symbol and ending at the second-last symbol does not contain any code word as substring. Every self-synchronizing code is a prefix code, but not all prefix codes are self-synchronizing. Other terms for self-synchronizing code are synchronized codeBerstel et al (2010) p. 137 or, ambiguously, comma-free code.Berstel & Perrin (1985) p. 377 A self-synchronizing code permits the proper framing of transmitted code words provided that no uncorrected errors occur in the symbol stream; external synchronization is not required. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UTF-8
UTF-8 is a variable-length character encoding used for electronic communication. Defined by the Unicode Standard, the name is derived from ''Unicode'' (or ''Universal Coded Character Set'') ''Transformation Format 8-bit''. UTF-8 is capable of encoding all 1,112,064 valid character code points in Unicode using one to four one-byte (8-bit) code units. Code points with lower numerical values, which tend to occur more frequently, are encoded using fewer bytes. It was designed for backward compatibility with ASCII: the first 128 characters of Unicode, which correspond one-to-one with ASCII, are encoded using a single byte with the same binary value as ASCII, so that valid ASCII text is valid UTF-8-encoded Unicode as well. UTF-8 was designed as a superior alternative to UTF-1, a proposed variable-length encoding with partial ASCII compatibility which lacked some features including self-synchronization and fully ASCII-compatible handling of characters such as slashes. Ken Thompson ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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