In query languages, path expressions identify an object by describing how to navigate to it
in some graph (possibly implicit) of objects. For example, the path expression p.Manager.Home.City might refer the city of residence of someone's manager.
Path expressions have been extended to support regular expression-like flexibility.
XPath is an example of a path expression language.
In concurrency control, path expressions are a mechanism for expressing permitted sequences of execution. For example, a path expression like " {read}, write" might specify that either multiple simultaneous executions of read or a single execution of write but not both are allowed at any point in time.
It is important to know that the path expressions are a mechanism for the synchronization of processes at the monitor level in the software. That provides a clear and structured approach to the description of shared data and the coordination and communication between concurrent processes. This method is flexible in its ability to express timing, and can be used in different ways.
In addition, path expressions are useful for process synchronization for two reasons: first, the close relationship between stream expressions and regular expressions that simplify the task of writing and reasoning about programs that use this synchronization mechanism. Second, synchronization in many concurrent programs in a finite state, and therefore can be adequately described by regular expressions. For precisely the same reasons, path expressions are useful for controlling the behavior of complicated asynchronous circuits. In fact, the finite state assumption may be even more reasonable at the hardware level than at the monitor level.
Path expressions provide a high level of descriptive synchronization that aids in the prevention and detection of design errors in complex systems and overcomes some of the dangers, such as certain forms of coding errors.
languages, pathexpressions identify an object by describing how to navigate to it in some graph (possibly implicit) of objects. For example, the path expression...
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...
the required data. JSONPath queries are pathexpressions written as strings, e.g. $.foo. The JSONPath expression $.store.book[0] applied to the following...
example of statement based syntax (whose syntax originates in COBOL) versus expression-based syntax (as in C/Java): ADD TAX TO PRICE. * is equivalent to PRICE...
control language Data definition language Data manipulation language Pathexpression Schmitt, Ingo (January 2008). "QQL: A DB&IR Query Language". The VDLB...
movements as an expression of their protest and frustration. American hard rock band Guns N' Roses quotes a speech by a Shining Path officer in their...
The expression as the crow flies is an idiom for the most direct path between two points. The meaning of the expression is attested from the early 19th...
Sub-selects Correlated sub-queries Regular expressions Common table expressions and writable common table expressions Encrypted connections via Transport Layer...
regular path query or RPQ is a query asking for pairs of endpoints in the database that are connected by a path satisfying a certain regular expression. A...
regular expression denial of service (ReDoS) is an algorithmic complexity attack that produces a denial-of-service by providing a regular expression and/or...
heterologous expression is often to determine the effects of mutations and differential interactions on protein function. It provides an easy path to efficiently...
out and attack them with sticks or other weapons. Metaphorically, this expression is also used to convey a public trial that one must overcome The word...
DOS/Windows paths, where the backslash is used as a path separator, requiring a doubled backslash \\ – this can then be re-escaped for a regular expression inside...
A path component, consisting of a sequence of path segments separated by a slash (/). A path is always defined for a URI, though the defined path may...
An expression vector, otherwise known as an expression construct, is usually a plasmid or virus designed for gene expression in cells. The vector is used...
that gives an expression for the mean free path: ℓ = ( σ n ) − 1 , {\displaystyle \ell =(\sigma n)^{-1},} where ℓ is the mean free path, n is the number...
this can be simplified using heuristic methods. Since this expression is a quotient of path integrals, it is naturally normalised. Since this formulation...
operands of the expression should not be modified on any path from the occurrence of that expression to the program point. The analysis is an example of a...
buttons, and check boxes. Info Path also uses controls such as Calculated Values, which display the result of xPathexpressions, and sections, which are containers...
The Expression of the Emotions in Man and Animals is Charles Darwin's third major work of evolutionary theory, following On the Origin of Species (1859)...
Path dependence is a concept in the social sciences, referring to processes where past events or decisions constrain later events or decisions. It can...
hierarchical queries are implemented by way of recursive common table expressions (CTEs). Unlike Oracle's earlier connect-by clause, recursive CTEs were...
4862, 16796, 58786, ... (sequence A000108 in the OEIS). An alternative expression for Cn is C n = ( 2 n n ) − ( 2 n n + 1 ) {\displaystyle C_{n}={2n \choose...
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