Whether the needle was located — an exact hit, or a fuzzy window at or above the threshold.
1 for an exact hit, otherwise the best window's Sørensen–Dice similarity; 0 when the fuzzy
pass was skipped or the needle was too short to score.
Word-index range of the located text in the normalized haystack; null when unmatched.
True when the match came from the exact (normalized substring) pass rather than the fuzzy window scan.