Class AdjacentTextNodeMerger

All Implemented Interfaces:
Serializable, SourceLocator, LocationProvider, SaxonLocator, InstructionInfo, Locator

public class AdjacentTextNodeMerger extends UnaryExpression
This class performs the first phase of processing in "constructing simple content": it takes an input sequence, eliminates empty text nodes, and combines adjacent text nodes into one.
Since:
9.3
See Also:
  • Constructor Details

    • AdjacentTextNodeMerger

      public AdjacentTextNodeMerger(Expression p0)
  • Method Details

    • typeCheck

      public Expression typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
      Description copied from class: UnaryExpression
      Type-check the expression. Default implementation for unary operators that accept any kind of operand
      Overrides:
      typeCheck in class UnaryExpression
      Parameters:
      visitor - an expression visitor
      contextItemType - the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to Type.ITEM_TYPE
      Returns:
      the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
      Throws:
      XPathException - if an error is discovered during this phase (typically a type error)
    • getItemType

      public ItemType getItemType(TypeHierarchy th)
      Determine the data type of the expression, if possible. The default implementation for unary expressions returns the item type of the operand
      Overrides:
      getItemType in class UnaryExpression
      Parameters:
      th - the type hierarchy cache
      Returns:
      the item type of the items in the result sequence, insofar as this is known statically.
    • computeCardinality

      public int computeCardinality()
      Description copied from class: UnaryExpression
      Determine the static cardinality. Default implementation returns the cardinality of the operand
      Overrides:
      computeCardinality in class UnaryExpression
      Returns:
      the computed cardinality, as one of the values StaticProperty.ALLOWS_ZERO_OR_ONE, StaticProperty.EXACTLY_ONE, StaticProperty.ALLOWS_ONE_OR_MORE, StaticProperty.ALLOWS_ZERO_OR_MORE
    • copy

      public Expression copy()
      Copy an expression. This makes a deep copy.
      Specified by:
      copy in class Expression
      Returns:
      the copy of the original expression
    • getImplementationMethod

      public int getImplementationMethod()
      An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). This method indicates which of these methods is prefered.
      Overrides:
      getImplementationMethod in class Expression
      Returns:
      the implementation method, for example Expression.ITERATE_METHOD or Expression.EVALUATE_METHOD or Expression.PROCESS_METHOD
    • iterate

      public SequenceIterator iterate(XPathContext context) throws XPathException
      Return an Iterator to iterate over the values of a sequence. The value of every expression can be regarded as a sequence, so this method is supported for all expressions. This default implementation handles iteration for expressions that return singleton values: for non-singleton expressions, the subclass must provide its own implementation.
      Overrides:
      iterate in class Expression
      Parameters:
      context - supplies the context for evaluation
      Returns:
      a SequenceIterator that can be used to iterate over the result of the expression
      Throws:
      XPathException - if any dynamic error occurs evaluating the expression
    • process

      public void process(XPathContext context, int locationId, int options) throws XPathException
      Process the instruction, without returning any tail calls
      Parameters:
      context - The dynamic context, giving access to the current node, the current variables, etc.
      Throws:
      XPathException
    • getExpressionName

      public String getExpressionName()
      Description copied from class: Expression
      Get a name identifying the kind of expression, in terms meaningful to a user.
      Overrides:
      getExpressionName in class Expression
      Returns:
      a name identifying the kind of expression, in terms meaningful to a user. The name will always be in the form of a lexical XML QName, and should match the name used in explain() output displaying the expression.
    • isTextNode

      public static boolean isTextNode(Item item)
      Ask whether an item is a text node
      Parameters:
      item - the item in question
      Returns:
      true if the item is a node of kind text