Package net.sf.saxon.pattern

This package provides classes associated with XSLT pattern handling.

See: Description

Interface Summary

Interface	Description
PatternParser	Interface to a parser of XSLT patterns.
PatternWithPredicate	Represents a pattern with a predicate, for example item[@value=3] or .[.
QNameTest	Interface for tests against a QName.
SchemaNodeTest	Marker interface for schema-element() and schema-attribute() node tests

Class Summary

Class	Description
AncestorQualifiedPattern	An AncestorQualifiedPattern represents a path of the form A/B or A//B, where nodes must match the pattern B and also have a parent/ancestor (respectively) that matches A.
AnchorPattern	This is a special pattern that matches the "anchor node".
AnyChildNodeTest	An AnyChildNodePattern is the pattern node(), which matches any node except a root node, an attribute node, or a namespace node: in other words, any node that is potentially the child of another node.
AnyNodeTest	NodeTest is an interface that enables a test of whether a node has a particular name and type.
BasePatternWithPredicate	Class for handling patterns with simple non-positional boolean predicates
BooleanExpressionPattern	A BooleanExpressionPattern is a pattern of the form .[ Expr ] introduced in XSLT 3.0.
CombinedNodeTest	A CombinedNodeTest combines two node tests using one of the operators union (=or), intersect (=and), difference (= "and not").
ContentTypeTest	NodeTest is an interface that enables a test of whether a node matches particular conditions.
DocumentNodeTest	A DocumentNodeTest implements the test document-node(element(~,~))
ExceptPattern	A pattern formed as the difference of two other patterns
GeneralNodePattern	A GeneralNodePattern represents a pattern which, because of the presence of positional predicates or otherwise, can only be evaluated "the hard way", by evaluating the equivalent expression with successive ancestors of the tested node as context item.
GeneralPositionalPattern	A GeneralPositionalPattern is a pattern of the form A[P] where A is an axis expression using the child axis and P is an expression that depends on the position.
IntersectPattern	A pattern formed as the difference of two other patterns
LocalNameTest	NodeTest is an interface that enables a test of whether a node has a particular name and type.
MultipleNodeKindTest	An MultipleNodeKindTest is a nodetest that matches nodes belonging to any subset of possible node kinds, for example element and document nodes, or attribute and namespace nodes
NamespaceTest	NodeTest is an interface that enables a test of whether a node has a particular name and type.
NameTest	NodeTest is an interface that enables a test of whether a node has a particular name and type.
NodeKindTest	NodeTest is an interface that enables a test of whether a node has a particular name and kind.
NodeSetPattern	A NodeSetPattern is a pattern based on an expression that is evaluated to return a set of nodes; a node matches the pattern if it is a member of this node-set.
NodeTest	A NodeTest is a simple kind of pattern that enables a context-free test of whether a node matches a given node kind and name.
NodeTestPattern	A NodeTestPattern is a pattern that consists simply of a NodeTest
Pattern	A Pattern represents the result of parsing an XSLT pattern string.
PatternMaker	This is a singleton class used to convert an expression to an equivalent pattern.
PatternParser30	Parser for XSLT patterns.
PatternThatSetsCurrent	This class represents a pattern that sets the value of current() to the node being matched, and then wraps another pattern that uses the value of current()
SameNameTest	NodeTest is an interface that enables a test of whether a node has a particular name and type.
SimplePositionalPattern	A SimplePositionalPattern is a pattern of the form A[N] where A is an axis expression using the child axis and P is a numeric literal.
StreamingFunctionArgumentPattern	This is a special pattern that matches the node supplied as the first argument of a call to a streamable stylesheet function; it corresponds to the pattern match="$arg" where $arg is the first argument of the function.
UnionPattern	A pattern formed as the union (or) of two other patterns
UnionQNameTest	A QNameTest that is the union of a number of supplied QNameTests
UniversalPattern	The UniversalPattern matches everything
VennPattern	Abstract pattern formed as the union, intersection, or difference of two other patterns; concrete subclasses are used for the different operators

Package net.sf.saxon.pattern Description

This package provides classes associated with XSLT pattern handling.

The principal classes are:

Pattern:
This represents an XSLT Pattern. There is a static method Pattern.make() which is used to construct a Pattern from a String (it is a factory method rather than a constructor, because it typically returns some subclass of Pattern according to the syntax supplied). Subclasses of Pattern represent different kinds of pattern such as LocationPathPattern and IDKeyPattern. What they all have in common is a match() method, which determines whether a given node matches the pattern. A pattern is not in itself an Expression, but the class PatternSponsor is used to wrap a pattern making it look like an expression for the benefit of the static analysis (allowing the same mechanisms to be used for example to find all the references to a variable).

NodeTest:
This represents a NodeTest within a step of an XPath expression. A NodeTest performs several roles: as well as its use in conjuction with an axis to form a step of a path expression, it acts as an ItemType used in handling type checking of nodes, and (wrapped in a NodeTestPattern) it acts as an XSLT pattern for use in constructs such as the match attribute of xsl:template and xsl:key. A NodeTest is used directly to implement simple patterns such as match="item" or match="*". There are several subclasses of NodeTest, depending on the conditions to be matched: node type, node name, namespace URI, and so on. The class AnyNodeTest matches any node, while NoNodeTest matches nothing. NodeTests can also be combined using the operators of intersection, difference, and union, to describe the more complex types that are sometimes computed by the type checking machinery.

Michael H. Kay
Saxonica Limited
9 February 2005