Package net.sf.saxon.expr

Class EmptyTextNodeRemover

java.lang.Object
net.sf.saxon.expr.Expression
net.sf.saxon.expr.UnaryExpression
net.sf.saxon.expr.EmptyTextNodeRemover
All Implemented Interfaces:
ExportAgent, ItemMappingFunction, Locatable, IdentityComparable, Traceable
public class EmptyTextNodeRemover extends UnaryExpression implements ItemMappingFunction
This class performs part of the processing in "constructing simple content": it takes an input sequence and eliminates empty text nodes into one.
Since:
9.3

  • Constructor Details

    • EmptyTextNodeRemover

      public EmptyTextNodeRemover(Expression p0)

  • Method Details

    • getItemType

      public ItemType getItemType()
      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
      Returns:
      the item type of the items in the result sequence, insofar as this is known statically.

    • computeCardinality

      protected 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. May also return StaticProperty.ALLOWS_ZERO if the result is known to be an empty sequence, or StaticProperty.ALLOWS_MANY if if is known to return a sequence of length two or more.

    • getOperandRole

      protected OperandRole getOperandRole()
      Description copied from class: UnaryExpression
      Get the usage (in terms of streamability analysis) of the single operand
      Specified by:
      getOperandRole in class UnaryExpression
      Returns:
      the operand usage

    • copy

      public Expression copy(RebindingMap rebindings)
      Copy an expression. This makes a deep copy.
      Specified by:
      copy in class Expression
      Parameters:
      rebindings - variables that must be re-bound
      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.
      Specified by:
      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

    • mapItem

      public Item mapItem(Item item) throws XPathException
      Map an item to another item
      Specified by:
      mapItem in interface ItemMappingFunction
      Parameters:
      item - The input item to be mapped.
      Returns:
      the result of the mapping: maybe null
      Throws:
      XPathException - probably can't happen

    • getStreamerName

      public String getStreamerName()
      Get the (partial) name of a class that supports streaming of this kind of expression
      Overrides:
      getStreamerName in class Expression
      Returns:
      the partial name of a class that can be instantiated to provide streaming support in Saxon-EE, or null if there is no such class

    • 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 export() output displaying the expression.

    • getElaborator

      public Elaborator getElaborator()
      Make an elaborator for this expression
      Overrides:
      getElaborator in class Expression
      Returns:
      a suitable elaborator