Class OpNothing

java.lang.Object
net.sf.saxon.regex.Operation
net.sf.saxon.regex.OpNothing

public class OpNothing extends Operation
Match empty string within a regular expression
  • Constructor Details

    • OpNothing

      public OpNothing()
  • Method Details

    • 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
    • matchesEmptyString

      public int matchesEmptyString()
      Description copied from class: Operation
      Ask whether the regular expression is known, after static analysis, to match a zero-length string
      Specified by:
      matchesEmptyString in class Operation
      Returns:
      a value indicating whether the regex is statically known to match a zero-length string. Specifically: Returning 0 means that it is not known statically whether or not the regex will match a zero-length string; this case typically arises when back-references are involved.
    • getMatchLength

      public int getMatchLength()
      Description copied from class: Operation
      Get the length of the matches returned by this operation if they are fixed-length
      Overrides:
      getMatchLength in class Operation
      Returns:
      the length of the matches, or -1 if the length is variable
    • 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