Class Idref

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

public class Idref extends SystemFunction
See Also:
  • Constructor Details

    • Idref

      public Idref()
  • Method Details

    • simplify

      public Expression simplify(ExpressionVisitor visitor) throws XPathException
      Simplify: add a second implicit argument, the context document
      Overrides:
      simplify in class FunctionCall
      Parameters:
      visitor - an expression visitor
      Returns:
      the simplified expression
      Throws:
      XPathException - if an error is discovered during expression rewriting
    • typeCheck

      public Expression typeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException
      Type-check the expression. This also calls preEvaluate() to evaluate the function if all the arguments are constant; functions that do not require this behavior can override the preEvaluate method.
      Overrides:
      typeCheck in class FunctionCall
      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)
    • checkArguments

      public void checkArguments(ExpressionVisitor visitor) throws XPathException
      Description copied from class: SystemFunction
      Method called during static type checking
      Overrides:
      checkArguments in class SystemFunction
      Parameters:
      visitor - the expression visitor
      Throws:
      XPathException
    • computeSpecialProperties

      public int computeSpecialProperties()
      Get the static properties of this expression (other than its type). The result is bit-signficant. These properties are used for optimizations. In general, if property bit is set, it is true, but if it is unset, the value is unknown.
      Overrides:
      computeSpecialProperties in class SystemFunction
      Returns:
      the special properties, as a bit-significant integer
    • preEvaluate

      public Expression preEvaluate(ExpressionVisitor visitor)
      preEvaluate: this method suppresses compile-time evaluation by doing nothing
      Overrides:
      preEvaluate in class FunctionCall
      Parameters:
      visitor - an expression visitor
      Returns:
      the result of the early evaluation, or the original expression, or potentially a simplified expression
    • copy

      public Expression copy()
      Copy an expression. This makes a deep copy.
      Overrides:
      copy in class SystemFunction
      Returns:
      the copy of the original expression
    • addToPathMap

      public PathMap.PathMapNodeSet addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)
      Add a representation of a doc() call or similar function to a PathMap. This is a convenience method called by the addToPathMap() methods for doc(), document(), collection() and similar functions. These all create a new root expression in the path map.
      Overrides:
      addToPathMap in class Expression
      Parameters:
      pathMap - the PathMap to which the expression should be added
      pathMapNodeSet -
      Returns:
      the pathMapNode representing the focus established by this expression, in the case where this expression is the first operand of a path expression or filter expression
    • iterate

      public SequenceIterator iterate(XPathContext context) throws XPathException
      Enumerate the results of the expression
      Specified by:
      iterate in interface SequenceIterable
      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
    • getIdrefMultiple

      public static SequenceIterator getIdrefMultiple(DocumentInfo doc, SequenceIterator keys, XPathContext context) throws XPathException
      Get the result when multiple idref values are supplied. Note this is also called from compiled XQuery code.
      Parameters:
      doc - the document to be searched
      keys - the idref values supplied
      context - the dynamic execution context
      Returns:
      iterator over the result of the function
      Throws:
      XPathException