hxt-xpath-8.5.4: The XPath modules for HXT.

Portabilityportable
Stabilityexperimental
MaintainerUwe Schmidt (uwe@fh-wedel.de)

Text.XML.HXT.XPath.XPathEval

Description

The core functions for evaluating the different types of XPath expressions. Each Expr-constructor is mapped to an evaluation function.

Synopsis

Documentation

getXPath :: String -> XmlTree -> XmlTreesSource

Select parts of a document by a string representing a XPath expression.

The main filter for selecting parts of a document via XPath. The string argument must be a XPath expression with an absolute location path, the argument tree must be a complete document tree. Result is a possibly empty list of XmlTrees forming the set of selected XPath values. XPath values other than XmlTrees (numbers, attributes, tagnames, ...) are converted to text nodes.

getXPathSubTrees :: String -> XmlTree -> XmlTreesSource

Select parts of an XML tree by a string representing an XPath expression.

The main filter for selecting parts of an arbitrary XML tree via XPath. The string argument must be a XPath expression with an absolute location path, There are no restrictions on the arument tree.

No canonicalization is performed before evaluating the query

Result is a possibly empty list of XmlTrees forming the set of selected XPath values. XPath values other than XmlTrees (numbers, attributes, tagnames, ...) are convertet to text nodes.

getXPathNodeSet' :: String -> XmlTree -> XmlNodeSetSource

compute the node set of an XPath query

getXPathWithNsEnv :: Attributes -> String -> XmlTree -> XmlTreesSource

Select parts of a document by a namespace aware XPath expression.

Works like getXPath but the prefix:localpart names in the XPath expression are interpreted with respect to the given namespace environment

getXPathSubTreesWithNsEnv :: Attributes -> String -> XmlTree -> XmlTreesSource

Same as getXPathSubTrees but with namespace aware XPath expression

getXPathNodeSetWithNsEnv' :: Attributes -> String -> XmlTree -> XmlNodeSetSource

compute the node set of a namespace aware XPath query

evalExpr :: Env -> Context -> Expr -> XPathFilterSource

The main evaluation entry point. Each XPath-Expr is mapped to an evaluation function. The Env-parameter contains the set of global variables for the evaluator, the Context-parameter the root of the tree in which the expression is evaluated.

parseXPathExpr :: String -> Either String ExprSource

parse an XPath expr string and return an expr tree or an error message. Namespaces are not taken into account.

parseXPathExprWithNsEnv :: Attributes -> String -> Either String ExprSource

parse an XPath expr string with a namespace environment for qualified names in the XPath expr and return an expr tree or an error message

getXPath' :: Expr -> XmlTree -> XmlTreesSource

Select parts of a document by an already parsed XPath expression

getXPathSubTrees' :: Expr -> XmlTree -> XmlTreesSource

Select parts of an XML tree by an XPath expression.

getXPathNodeSet'' :: Expr -> XmlTree -> XmlNodeSetSource

compute the node set of an XPath query for an already parsed XPath expr