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Naming Collision
A naming collision is a circumstance where two or more identifiers in a given namespace or a given scope cannot be unambiguously resolved, and such unambiguous resolution is a requirement of the underlying system. Example: XML element names In XML, element names can be originated and changed to reflect the type of information contained in the document. This level of flexibility may cause problems if separate documents encode different kinds of information, but use the same identifiers for the element names. For example, the following sample document defines the basic semantics for a "person" document and a "book" document. Both of these use a "title" element, but the meaning is not the same: Nancy Davolio Dr. 29 Harry Potter And The Cursed Child ABCD1234567 For an application to allow a user to correctly query for and retrieve the "title" element, it must provide a way to unambiguously specify ''which' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Identifiers
An identifier is a name that identifies (that is, labels the identity of) either a unique object or a unique ''class'' of objects, where the "object" or class may be an idea, person, physical countable object (or class thereof), or physical mass noun, noncountable substance (or class thereof). The abbreviation ID often refers to identity, identification (the process of identifying), or an identifier (that is, an instance of identification). An identifier may be a word, number, letter, symbol, or any combination of those. The words, numbers, letters, or symbols may follow an code, encoding system (wherein letters, digits, words, or symbols ''stand for'' [represent] ideas or longer names) or they may simply be arbitrary. When an identifier follows an encoding system, it is often referred to as a code or id code. For instance the ISO/IEC 11179 metadata registry standard defines a code as ''system of valid symbols that substitute for longer values'' in contrast to identifiers wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Namespace
In computing, a namespace is a set of signs (''names'') that are used to identify and refer to objects of various kinds. A namespace ensures that all of a given set of objects have unique names so that they can be easily identified. Namespaces are commonly structured as hierarchies to allow reuse of names in different contexts. As an analogy, consider a system of naming of people where each person has a given name, as well as a family name shared with their relatives. If the first names of family members are unique only within each family, then each person can be uniquely identified by the combination of first name and family name; there is only one Jane Doe, though there may be many Janes. Within the namespace of the Doe family, just "Jane" suffices to unambiguously designate this person, while within the "global" namespace of all people, the full name must be used. Prominent examples for namespaces include file systems, which assign names to files. Some programming languages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scope (programming)
In computer programming, the scope of a name binding (an association of a name to an entity, such as a variable) is the part of a program where the name binding is valid; that is, where the name can be used to refer to the entity. In other parts of the program, the name may refer to a different entity (it may have a different binding), or to nothing at all (it may be unbound). Scope helps prevent name collisions by allowing the same name to refer to different objects – as long as the names have separate scopes. The scope of a name binding is also known as the visibility of an entity, particularly in older or more technical literature—this is in relation to the referenced entity, not the referencing name. The term "scope" is also used to refer to the set of ''all'' name bindings that are valid within a part of a program or at a given point in a program, which is more correctly referred to as ''context'' or ''environment''. Strictly speaking and in practice for most programmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Name Resolution (programming Languages)
In programming languages, name resolution is the resolution of the tokens within program expressions to the intended program components. Overview Expressions in computer programs reference variables, data types, functions, classes, objects, libraries, packages and other entities by name. In that context, name resolution refers to the association of those not-necessarily-unique names with the intended program entities. The algorithms that determine what those identifiers refer to in specific contexts are part of the language definition. The complexity of these algorithms is influenced by the sophistication of the language. For example, name resolution in assembly language usually involves only a single simple table lookup, while name resolution in C++ is extremely complicated as it involves: * namespaces, which make it possible for an identifier to have different meanings depending on its associated namespace; * scopes, which make it possible for an identifier to have differen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XPath
XPath (XML Path Language) is an expression language designed to support the query or transformation of XML documents. It was defined by the World Wide Web Consortium (W3C) in 1999, and can be used to compute values (e.g., strings, numbers, or Boolean values) from the content of an XML document. Support for XPath exists in applications that support XML, such as web browsers, and many programming languages. The XPath language is based on a tree representation of the XML document, and provides the ability to navigate around the tree, selecting nodes by a variety of criteria. In popular use (though not in the official specification), an XPath expression is often referred to simply as "an XPath". Originally motivated by a desire to provide a common syntax and behavior model between XPointer and XSLT, subsets of the XPath query language are used in other W3C specifications such as XML Schema, XForms and the Internationalization Tag Set (ITS). XPath has been adopted by a num ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collision Domain
A collision domain is a network segment (connected by a shared medium or through repeaters) where simultaneous data transmissions collide with one another as a result of more than one device attempting to send a packet on the network segment at the same time. The collision domain applies particularly in wireless networks, but also affected early versions of Ethernet. Members of a collision domain may be involved in collisions with one another. Devices outside the collision domain do not have collisions with those inside. A channel access method dictates that only one device in the collision domain may transmit at any one time, and the other devices in the domain listen to the network and refrain from transmitting while others are already transmitting in order to avoid collisions. Because only one device may be transmitting at any one time, total network bandwidth is shared among all devices on the collision domain. Collisions also decrease network efficiency in a collision domain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Programming
Computer programming or coding is the composition of sequences of instructions, called programs, that computers can follow to perform tasks. It involves designing and implementing algorithms, step-by-step specifications of procedures, by writing 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 application domain, details of programming languages and generic code libraries, specialized algorithms, and formal logic. Auxiliary tasks accompanying and related to programming include analyzing requirements, testing, debugging (investigating and fixing problems), implementation of build systems, and management of derived artifacts, such as programs' machine code. While these are sometimes considered prog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Name Collision
In computer programming, a name collision is the nomenclature problem that occurs when the same variable name is used for different things in two separate areas that are joined, merged, or otherwise go from occupying separate namespaces to sharing one. As with the collision of other identifiers, it must be resolved in some way for the new software (such as a mashup) to work right. "Getting Started" (lesson for C++), Brown University, Computer Science Dept., January 2000 (in text as "Jan 2000"), pages 5-6, webpage (PDF): CS-Brown-Cpp Problems of name collision, and methods to avoid them, are a common issue in an introductory level analysis of computer languages, such as for C++. __TOC__ History The term "name collision" has been used in computer science for more than three decades, when referring to names in various classification systems. "Name collision in multiple classification hierarchies", Portal ACM (Association for Computing Machinery), by J.L. Knudsen, 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Namespace
In computing, a namespace is a set of signs (''names'') that are used to identify and refer to objects of various kinds. A namespace ensures that all of a given set of objects have unique names so that they can be easily identified. Namespaces are commonly structured as hierarchies to allow reuse of names in different contexts. As an analogy, consider a system of naming of people where each person has a given name, as well as a family name shared with their relatives. If the first names of family members are unique only within each family, then each person can be uniquely identified by the combination of first name and family name; there is only one Jane Doe, though there may be many Janes. Within the namespace of the Doe family, just "Jane" suffices to unambiguously designate this person, while within the "global" namespace of all people, the full name must be used. Prominent examples for namespaces include file systems, which assign names to files. Some programming languages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XML Namespaces
XML namespaces are used for providing uniquely named elements and attributes in an XML document. They are defined in a W3C recommendation. An XML instance may contain element or attribute names from more than one XML vocabulary. If each vocabulary is given a namespace, the ambiguity between identically named elements or attributes can be resolved. A simple example would be to consider an XML instance that contained references to a customer and an ordered product. Both the customer element and the product element could have a child element named id. References to the id element would therefore be ambiguous; placing them in different namespaces would remove the ambiguity. Namespace names A ''namespace name'' is a uniform resource identifier (URI). Typically, the URI chosen for the namespace of a given XML vocabulary describes a resource under the control of the author or organization defining the vocabulary, such as a URL for the author's Web server. However, the namespace specif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delimiter Collision
A delimiter is a sequence of one or more characters for specifying the boundary between separate, independent regions in plain text, mathematical expressions or other data streams. An example of a delimiter is the comma character, which acts as a ''field delimiter'' in a sequence of comma-separated values. Another example of a delimiter is the time gap used to separate letters and words in the transmission of Morse code. In mathematics, delimiters are often used to specify the scope of an operation, and can occur both as isolated symbols (e.g., colon in "1 : 4") and as a pair of opposing-looking symbols (e.g., angled brackets in \langle a, b \rangle). Delimiters represent one of various means of specifying boundaries in a data stream. Declarative notation, for example, is an alternate method (without the use of delimiters) that uses a length field at the start of a data stream to specify the number of characters that the data stream contains. describing the method in Hol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
