Package net.sf.saxon.pattern
Class IDPattern
- java.lang.Object
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- net.sf.saxon.pattern.Pattern
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- net.sf.saxon.pattern.IDPattern
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- All Implemented Interfaces:
java.io.Serializable
,javax.xml.transform.SourceLocator
,Container
public final class IDPattern extends Pattern
An IDPattern is a pattern of the form id("literal") or id($variable)- See Also:
- Serialized Form
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Constructor Summary
Constructors Constructor Description IDPattern(Expression id)
Create an id pattern.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description Pattern
analyze(StaticContext env, ItemType contextItemType)
Type-check the pattern.int
getDependencies()
Get the dependencies of the pattern.int
getNodeKind()
Determine the type of nodes to which this pattern applies.NodeTest
getNodeTest()
Get a NodeTest that all the nodes matching this pattern must satisfyjava.util.Iterator
iterateSubExpressions()
Iterate over the subexpressions within this patternboolean
matches(NodeInfo e, XPathContext context)
Determine whether this Pattern matches the given Nodevoid
promote(PromotionOffer offer)
Offer promotion for subexpressions within this pattern.-
Methods inherited from class net.sf.saxon.pattern.Pattern
getColumnNumber, getDefaultPriority, getExecutable, getFingerprint, getHostLanguage, getLineNumber, getLocationProvider, getPublicId, getSystemId, internalMatches, make, replaceSubExpression, setExecutable, setLineNumber, setOriginalText, setSystemId, simplify, toString
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Constructor Detail
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IDPattern
public IDPattern(Expression id)
Create an id pattern.- Parameters:
id
- Either a StringValue or a VariableReference
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Method Detail
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analyze
public Pattern analyze(StaticContext env, ItemType contextItemType) throws XPathException
Type-check the pattern. Default implementation does nothing. This is only needed for patterns that contain variable references or function calls.- Overrides:
analyze
in classPattern
- Returns:
- the optimised Pattern
- Throws:
XPathException
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getDependencies
public int getDependencies()
Get the dependencies of the pattern. The only possible dependency for a pattern is on local variables. This is analyzed in those patterns where local variables may appear.- Overrides:
getDependencies
in classPattern
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iterateSubExpressions
public java.util.Iterator iterateSubExpressions()
Iterate over the subexpressions within this pattern- Overrides:
iterateSubExpressions
in classPattern
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promote
public void promote(PromotionOffer offer) throws XPathException
Offer promotion for subexpressions within this pattern. The offer will be accepted if the subexpression is not dependent on the factors (e.g. the context item) identified in the PromotionOffer. By default the offer is not accepted - this is appropriate in the case of simple expressions such as constant values and variable references where promotion would give no performance advantage. This method is always called at compile time.Unlike the corresponding method on
Expression
, this method does not return anything: it can make internal changes to the pattern, but cannot return a different pattern. Only certain kinds of promotion are applicable within a pattern: specifically, promotions affecting local variable references within the pattern.- Overrides:
promote
in classPattern
- Parameters:
offer
- details of the offer, for example the offer to move expressions that don't depend on the context to an outer level in the containing expression- Throws:
XPathException
- if any error is detected
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matches
public boolean matches(NodeInfo e, XPathContext context) throws XPathException
Determine whether this Pattern matches the given Node- Specified by:
matches
in classPattern
- Parameters:
e
- The NodeInfo representing the Element or other node to be tested against the Patterncontext
- The dynamic context. Only relevant if the pattern uses variables, or contains calls on functions such as document() or key().- Returns:
- true if the node matches the Pattern, false otherwise
- Throws:
XPathException
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getNodeKind
public int getNodeKind()
Determine the type of nodes to which this pattern applies.- Overrides:
getNodeKind
in classPattern
- Returns:
- Type.ELEMENT
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getNodeTest
public NodeTest getNodeTest()
Get a NodeTest that all the nodes matching this pattern must satisfy- Specified by:
getNodeTest
in classPattern
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