Class HashedSequenceComparator<S extends Sequence>

  • Type Parameters:
    S - the base sequence type.

    public final class HashedSequenceComparator<S extends Sequence>
    extends SequenceComparator<HashedSequence<S>>
    Wrap another comparator for use with HashedSequence.

    This comparator acts as a proxy for the real comparator, evaluating the cached hash code before testing the underlying comparator's equality. Comparators of this type must be used with a HashedSequence.

    To construct an instance of this type use HashedSequencePair.

    • Method Detail

      • equals

        public boolean equals​(HashedSequence<S> a,
                              int ai,
                              HashedSequence<S> b,
                              int bi)
        Compare two items to determine if they are equivalent. It is permissible to compare sequence a with itself (by passing a again in position b).
        Specified by:
        equals in class SequenceComparator<HashedSequence<S extends Sequence>>
        a - the first sequence.
        ai - item of ai to compare.
        b - the second sequence.
        bi - item of bi to compare.
        true if the two items are identical according to this function's equivalence rule.
      • hash

        public int hash​(HashedSequence<S> seq,
                        int ptr)
        Get a hash value for an item in a sequence. If two items are equal according to this comparator's SequenceComparator.equals(Sequence, int, Sequence, int) method, then this hash method must produce the same integer result for both items. It is not required for two items to have different hash values if they are unequal according to the equals() method.
        Specified by:
        hash in class SequenceComparator<HashedSequence<S extends Sequence>>
        seq - the sequence.
        ptr - the item to obtain the hash for.
        hash the hash value.