- /* Choose the longer suffix. Return the first byte of the right
- half, rather than the last byte of the left half. */
+ /* Choose the shorter suffix. Return the index of the first byte of
+ the right half, rather than the last byte of the left half.
+
+ For some examples, 'banana' has two critical factorizations, both
+ exposed by the two lexicographic extreme suffixes of 'anana' and
+ 'nana', where both suffixes have a period of 2. On the other
+ hand, with 'aab' and 'bba', both strings have a single critical
+ factorization of the last byte, with the suffix having a period
+ of 1. While the maximal lexicographic suffix of 'aab' is 'b',
+ the maximal lexicographic suffix of 'bba' is 'ba', which is not a
+ critical factorization. Conversely, the maximal reverse
+ lexicographic suffix of 'a' works for 'bba', but not 'ab' for
+ 'aab'. The shorter suffix of the two will always be a critical
+ factorization. */