Class OpNothing


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

      • OpNothing

        public OpNothing()
    • Method Detail

      • 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 java.lang.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