def decompose_seeds(seq, seedsize):
    """Break up a sequence into seeds.

    Seeds are essentially k-mers, but we use different terminology for here two
    reasons.

    1. These sequences are used specifically as anchors.
    2. We want to distinguish between k size (for k-mer counting) and seed size
       (for definining reference target sequences), which often have different
       optimal values.
    """
    for i in range(len(seq) - seedsize + 1):
        yield seq[i:i + seedsize]
