Package net.sf.saxon.regex

Class OpBackReference

java.lang.Object
net.sf.saxon.regex.Operation
net.sf.saxon.regex.OpBackReference
public class OpBackReference extends Operation
A back-reference in a regular expression

  • Method Details

    • matchesEmptyString

      public int matchesEmptyString()
      Ask whether the regular expression is known, after static analysis, to match a zero-length string
      Specified by:
      matchesEmptyString in class Operation
      Returns:
      false. Returning true means that the expression is known statically to match ""; returning false means that this cannot be determined statically; it does not mean that the expression does not match "". We cannot do the analysis statically where back-references are involved, so we return false.

    • iterateMatches

      public IntIterator iterateMatches(REMatcher matcher, int position)
      Description copied from class: Operation
      Get an iterator returning all the matches for this operation
      Specified by:
      iterateMatches in class Operation
      Parameters:
      matcher - supplies the context for the matching; may be updated with information about captured groups
      position - the start position to seek a match
      Returns:
      an iterator returning the endpoints of all matches starting at the supplied position

    • display

      public String display()
      Display the operation as a regular expression, possibly in abbreviated form
      Specified by:
      display in class Operation
      Returns:
      the operation in a form that is recognizable as a regular expression or abbreviated regular expression