KeyPattern

java.lang.Object
- net.sf.saxon.pattern.Pattern
- - net.sf.saxon.pattern.KeyPattern

All Implemented Interfaces:

java.io.Serializable, javax.xml.transform.SourceLocator, Container, PatternFinder
```
public final class KeyPattern
extends Pattern
```
A KeyPattern is a pattern of the form key(keyname, keyvalue)

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor Description

KeyPattern(StructuredQName keyName, Expression key)
Constructor

Constructors
Constructor	Description
`KeyPattern(StructuredQName keyName, Expression key)`	Constructor

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`allocateSlots(StaticContext env, SlotManager slotManager, int nextFree)`	Allocate slots to any variables used within the pattern
`Pattern`	`analyze(ExpressionVisitor visitor, ItemType contextItemType)`	Type-check the pattern.
`boolean`	`equals(java.lang.Object other)`	Determine whether this pattern is the same as another pattern
`int`	`getDependencies()`	Get the dependencies of the pattern.
`NodeTest`	`getNodeTest()`	Get a NodeTest that all the nodes matching this pattern must satisfy
`int`	`hashCode()`	Hashcode supporting equals()
`java.util.Iterator`	`iterateSubExpressions()`	Iterate over the subexpressions within this pattern
`boolean`	`matches(NodeInfo e, XPathContext context)`	Determine whether this Pattern matches the given Node.
`void`	`promote(PromotionOffer offer)`	Offer promotion for subexpressions within this pattern.
`boolean`	`replaceSubExpression(Expression original, Expression replacement)`	Replace one subexpression by a replacement subexpression

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from class net.sf.saxon.pattern.Pattern
getColumnNumber, getDefaultPriority, getExecutable, getFingerprint, getHostLanguage, getLineNumber, getLocationProvider, getNodeKind, getPublicId, getSystemId, internalMatches, make, makeSearchExpression, selectNodes, setExecutable, setLineNumber, setOriginalText, setSystemId, simplify, toString

- Constructor Detail
  - KeyPattern
```
public KeyPattern(StructuredQName keyName,
                  Expression key)
```
    Constructor
    
    Parameters:
    
    keyName - the name of the key
    
    key - the value of the key: either a StringValue or a VariableReference
- Method Detail
  - analyze
```
public Pattern analyze(ExpressionVisitor visitor,
                       ItemType contextItemType)
                throws XPathException
```
    Type-check the pattern. This is needed for patterns that contain variable references or function calls.
    
    Overrides:
    
    analyze in class Pattern
    
    Parameters:
    
    visitor - the expression visitor
    
    contextItemType - the type of the context item, if known, at the point where the pattern is defined
    
    Returns:
    
    the optimised Pattern
    
    Throws:
    
    XPathException
  - 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 class Pattern
    
    Returns:
    
    the dependencies, as a bit-significant mask
  - iterateSubExpressions
```
public java.util.Iterator iterateSubExpressions()
```
    Iterate over the subexpressions within this pattern
    
    Overrides:
    
    iterateSubExpressions in class Pattern
    
    Returns:
    
    an iterator over the subexpressions. Default implementation returns an empty sequence
  - 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 class Pattern
    
    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
  - replaceSubExpression
```
public boolean replaceSubExpression(Expression original,
                                    Expression replacement)
```
    Description copied from interface: Container
    
    Replace one subexpression by a replacement subexpression
    
    Specified by:
    
    replaceSubExpression in interface Container
    
    Overrides:
    
    replaceSubExpression in class Pattern
    
    Parameters:
    
    original - the original subexpression
    
    replacement - the replacement subexpression
    
    Returns:
    
    true if the original subexpression was found
  - allocateSlots
```
public int allocateSlots(StaticContext env,
                         SlotManager slotManager,
                         int nextFree)
```
    Allocate slots to any variables used within the pattern
    
    Overrides:
    
    allocateSlots in class Pattern
    
    Parameters:
    
    env - the static context in the XSLT stylesheet
    
    slotManager - the slot manager representing the stack frame for local variables
    
    nextFree - the next slot that is free to be allocated @return the next slot that is free to be allocated
  - matches
```
public boolean matches(NodeInfo e,
                       XPathContext context)
                throws XPathException
```
    Determine whether this Pattern matches the given Node.
    
    Specified by:
    
    matches in class Pattern
    
    Parameters:
    
    e - The NodeInfo representing the Element or other node to be tested against the Pattern
    
    context - 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
  - getNodeTest
```
public NodeTest getNodeTest()
```
    Get a NodeTest that all the nodes matching this pattern must satisfy
    
    Specified by:
    
    getNodeTest in class Pattern
    
    Returns:
    
    a NodeTest, as specific as possible, which all the matching nodes satisfy
  - equals
```
public boolean equals(java.lang.Object other)
```
    Determine whether this pattern is the same as another pattern
    
    Overrides:
    
    equals in class java.lang.Object
    
    Parameters:
    
    other - the other object
  - hashCode
```
public int hashCode()
```
    Hashcode supporting equals()
    
    Overrides:
    
    hashCode in class java.lang.Object

Class KeyPattern

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from class net.sf.saxon.pattern.Pattern

Constructor Detail

KeyPattern

Method Detail

analyze

getDependencies

iterateSubExpressions

promote

replaceSubExpression

allocateSlots

matches

getNodeTest

equals

hashCode