Package net.sf.saxon.pattern
Class ConditionalPattern
- java.lang.Object
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- net.sf.saxon.pattern.Pattern
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- net.sf.saxon.pattern.ConditionalPattern
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- All Implemented Interfaces:
java.io.Serializable
,javax.xml.transform.SourceLocator
,Container
,PatternFinder
public class ConditionalPattern extends Pattern
A ConditionalPattern tests a node against one of a number of patterns depending on the value of a condition. This is used only as a streaming selection.- See Also:
- Serialized Form
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Constructor Summary
Constructors Constructor Description ConditionalPattern(Expression[] conditions, Pattern[] patterns)
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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 patternPattern
analyze(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType)
Type-check the pattern.boolean
equals(java.lang.Object other)
Determine whether this pattern is the same as another patternint
getDependencies()
Get the dependencies of the pattern.ItemType
getItemType()
Get a NodeTest that all the nodes matching this pattern must satisfyint
getNodeKind()
Determine the types of nodes to which this pattern applies.int
hashCode()
Hashcode supporting equals()java.util.Iterator
iterateSubExpressions()
Iterate over the subexpressions within this patternboolean
matches(Item item, XPathContext context)
Determine if the supplied node matches the patternboolean
matchesBeneathAnchor(NodeInfo node, NodeInfo anchor, XPathContext context)
Determine whether this pattern matches a given Node within the subtree rooted at a given anchor node.void
promote(PromotionOffer offer, Expression parent)
Offer promotion for subexpressions within this pattern.boolean
replaceSubExpression(Expression original, Expression replacement)
Replace a subexpression by a replacement subexpressionvoid
setExecutable(Executable executable)
Set the executable containing this patternvoid
setLineNumber(int lineNumber)
Override method to set the line numbervoid
setOriginalText(java.lang.String pattern)
Set the original textvoid
setSystemId(java.lang.String systemId)
Override method to set the system IDPattern
simplify(ExpressionVisitor visitor)
Simplify the pattern: perform any context-independent optimisations-
Methods inherited from class net.sf.saxon.pattern.Pattern
getColumnNumber, getContainerGranularity, getDefaultPriority, getExecutable, getFingerprint, getHostLanguage, getLineNumber, getLocationProvider, getPublicId, getSystemId, internalMatches, make, resolveCurrent, selectNodes, setVariableBindingExpression, toString
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Constructor Detail
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ConditionalPattern
public ConditionalPattern(Expression[] conditions, Pattern[] patterns)
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Method Detail
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setExecutable
public void setExecutable(Executable executable)
Set the executable containing this pattern- Overrides:
setExecutable
in classPattern
- Parameters:
executable
- the executable
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simplify
public Pattern simplify(ExpressionVisitor visitor) throws XPathException
Simplify the pattern: perform any context-independent optimisations- Overrides:
simplify
in classPattern
- Parameters:
visitor
- an expression visitor- Returns:
- the optimised Pattern
- Throws:
XPathException
- if a static error is discovered
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analyze
public Pattern analyze(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
Type-check the pattern. This is only needed for patterns that contain variable references or function calls.- Overrides:
analyze
in classPattern
- Parameters:
visitor
- the expression visitorcontextItemType
- the type of the context item at the point where the pattern is defined. Set to null if it is known that the context item is undefined.- Returns:
- the optimised Pattern
- Throws:
XPathException
- if a static error is discovered
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promote
public void promote(PromotionOffer offer, Expression parent) 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 expressionparent
-- Throws:
XPathException
- if any error is detected
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replaceSubExpression
public boolean replaceSubExpression(Expression original, Expression replacement)
Replace a subexpression by a replacement subexpression- Overrides:
replaceSubExpression
in classPattern
- Parameters:
original
- the expression to be replacedreplacement
- the new expression to be inserted in its place- Returns:
- true if the replacement was carried out
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setOriginalText
public void setOriginalText(java.lang.String pattern)
Set the original text- Overrides:
setOriginalText
in classPattern
- Parameters:
pattern
- the original text of the pattern
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allocateSlots
public int allocateSlots(StaticContext env, SlotManager slotManager, int nextFree)
Allocate slots to any variables used within the pattern- Overrides:
allocateSlots
in classPattern
- Parameters:
env
- the static context in the XSLT stylesheetslotManager
-nextFree
- the next slot that is free to be allocated @return the next slot that is free to be allocated- Returns:
- the next slot that is free to be allocated
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matches
public boolean matches(Item item, XPathContext context) throws XPathException
Determine if the supplied node matches the pattern- Specified by:
matches
in classPattern
- Parameters:
item
- the node to be comparedcontext
- 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 either of the operand patterns
- Throws:
XPathException
- if a dynamic error occurs during pattern matching
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matchesBeneathAnchor
public boolean matchesBeneathAnchor(NodeInfo node, NodeInfo anchor, XPathContext context) throws XPathException
Determine whether this pattern matches a given Node within the subtree rooted at a given anchor node. This method is used when the pattern is used for streaming.- Overrides:
matchesBeneathAnchor
in classPattern
- Parameters:
node
- The NodeInfo representing the Element or other node to be tested against the Patternanchor
- The anchor node, which must match any AnchorPattern subpatterncontext
- 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
- if a dynamic error occurs during pattern matching
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getNodeKind
public int getNodeKind()
Determine the types of nodes to which this pattern applies. Used for optimisation. For patterns that match nodes of several types, return Type.NODE- Overrides:
getNodeKind
in classPattern
- Returns:
- the type of node matched by this pattern. e.g. Type.ELEMENT or Type.TEXT
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getItemType
public ItemType getItemType()
Get a NodeTest that all the nodes matching this pattern must satisfy- Specified by:
getItemType
in classPattern
- Returns:
- an ItemType, as specific as possible, which all the matching items satisfy
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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
- Returns:
- the dependencies, as a bit-significant mask
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iterateSubExpressions
public java.util.Iterator iterateSubExpressions()
Iterate over the subexpressions within this pattern- Overrides:
iterateSubExpressions
in classPattern
- Returns:
- an iterator over the subexpressions.
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setSystemId
public void setSystemId(java.lang.String systemId)
Override method to set the system ID- Overrides:
setSystemId
in classPattern
- Parameters:
systemId
- the URI of the module containing the pattern
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setLineNumber
public void setLineNumber(int lineNumber)
Override method to set the line number- Overrides:
setLineNumber
in classPattern
- Parameters:
lineNumber
- the line number of the pattern in the source module
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equals
public boolean equals(java.lang.Object other)
Determine whether this pattern is the same as another pattern- Overrides:
equals
in classjava.lang.Object
- Parameters:
other
- the other object
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hashCode
public int hashCode()
Hashcode supporting equals()- Overrides:
hashCode
in classjava.lang.Object
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