Class Substring

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

public class Substring extends SystemFunction
This class implements the XPath substring() function
See Also:
  • Constructor Details

    • Substring

      public Substring()
  • Method Details

    • evaluateItem

      public Item evaluateItem(XPathContext context) throws XPathException
      Evaluate the function
      Specified by:
      evaluateItem in interface EvaluableItem
      Overrides:
      evaluateItem in class Expression
      Parameters:
      context - The context in which the expression is to be evaluated
      Returns:
      the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
      Throws:
      XPathException - if any dynamic error occurs evaluating the expression
    • substring

      public static CharSequence substring(StringValue sv, NumericValue start)
      Implement the substring function with two arguments.
      Parameters:
      sv - the string value
      start - the numeric offset (1-based) of the first character to be included in the result (if not an integer, the XPath rules apply)
      Returns:
      the substring starting at this position.
    • substring

      public static CharSequence substring(StringValue sv, NumericValue start, NumericValue len, XPathContext context)
      Implement the substring function with three arguments.
      Parameters:
      sv - the string value
      start - the numeric offset (1-based) of the first character to be included in the result (if not an integer, the XPath rules apply)
      len - the length of the required substring (again, XPath rules apply)
      context - the XPath dynamic context. Provided because some arithmetic computations require it
      Returns:
      the substring starting at this position.