## net.sf.saxon.pattern
Class ConditionalPattern

    java.lang.Object
      net.sf.saxon.pattern.Pattern
          net.sf.saxon.pattern.ConditionalPattern

All Implemented Interfaces:
  Serializable, 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

Constructor Summary
`ConditionalPattern(Expression[] conditions, Pattern[] patterns)`

Method Summary
`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(Object other)` Determine whether this pattern is the same as another pattern
`int` `getDependencies()` Get the dependencies of the pattern.
`int` `getNodeKind()` Determine the types of nodes to which this pattern applies.
`NodeTest` `getNodeTest()` Get a NodeTest that all the nodes matching this pattern must satisfy
`int` `hashCode()` Hashcode supporting equals()
`Iterator` `iterateSubExpressions()` Iterate over the subexpressions within this pattern
`boolean` `matches(NodeInfo e, XPathContext context)` Determine if the supplied node matches the pattern
`boolean` `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 subexpression
`void` `setExecutable(Executable executable)` Set the executable containing this pattern
`void` `setLineNumber(int lineNumber)` Override method to set the line number
`void` `setOriginalText(String pattern)` Set the original text
`void` `setSystemId(String systemId)` Override method to set the system ID
`Pattern` `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, makeSearchExpression, resolveCurrent, selectNodes, toString`

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

Constructor Detail

### ConditionalPattern

    public ConditionalPattern(Expression[] conditions,
                              Pattern[] patterns)

Method Detail

### setExecutable

    public void setExecutable(Executable executable)

  Set the executable containing this pattern

  Overrides:
    `setExecutable` in class `Pattern`
  Parameters:
    `executable` - the executable

### simplify

    public Pattern simplify(ExpressionVisitor visitor)
                     throws XPathException

  Simplify the pattern: perform any context-independent optimisations

  Overrides:
    `simplify` in class `Pattern`
  Parameters:
    `visitor` - an expression visitor
  Returns:
    the optimised Pattern
  Throws:
    `XPathException`

### analyze

    public Pattern analyze(ExpressionVisitor visitor,
                           ItemType contextItemType)
                    throws XPathException

  Type-check the pattern. This is only 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 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`

### 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 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
    `parent` -
  Throws:
    `XPathException` - if any error is detected

### replaceSubExpression

    public boolean replaceSubExpression(Expression original,
                                        Expression replacement)

  Replace a subexpression by a replacement subexpression

  Overrides:
    `replaceSubExpression` in class `Pattern`
  Parameters:
    `original` - the expression to be replaced
    `replacement` - the new expression to be inserted in its place
  Returns:
    true if the replacement was carried out

### setOriginalText

    public void setOriginalText(String pattern)

  Set the original text

  Overrides:
    `setOriginalText` in class `Pattern`
  Parameters:
    `pattern` - the original text of the pattern

### 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` -
    `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 if the supplied node matches the pattern

  Specified by:
    `matches` in class `Pattern`
  Parameters:
    `e` - the node to be compared
    `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 either of the operand patterns
  Throws:
    `XPathException`

### 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 class `Pattern`
  Parameters:
    `node` - The NodeInfo representing the Element or other node to be tested against the Pattern
    `anchor` - The anchor node, which must match any AnchorPattern subpattern
    `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`

### 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 class `Pattern`
  Returns:
    the type of node matched by this pattern. e.g. Type.ELEMENT or Type.TEXT

### 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

### 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 Iterator iterateSubExpressions()

  Iterate over the subexpressions within this pattern

  Overrides:
    `iterateSubExpressions` in class `Pattern`
  Returns:
    an iterator over the subexpressions.

### setSystemId

    public void setSystemId(String systemId)

  Override method to set the system ID

  Overrides:
    `setSystemId` in class `Pattern`
  Parameters:
    `systemId` - the URI of the module containing the pattern

### setLineNumber

    public void setLineNumber(int lineNumber)

  Override method to set the line number

  Overrides:
    `setLineNumber` in class `Pattern`
  Parameters:
    `lineNumber` - the line number of the pattern in the source module

### equals

    public boolean equals(Object other)

  Determine whether this pattern is the same as another pattern

  Overrides:
    `equals` in class `Object`
  Parameters:
    `other` - the other object

### hashCode

    public int hashCode()

  Hashcode supporting equals()

  Overrides:
    `hashCode` in class `Object`

Copyright (c) 2004-2010 Saxonica Limited. All rights reserved.