ref: 7e6d7d36f83f05f372cfbce43534a2747bfc39c3 dir: /test/t.aeiouy/
/^[^aeiouy]*a[^aeiouy]*e[^aeiouy]*i[^aeiouy]*o[^aeiouy]*u[^aeiouy]*y[^aeiouy]*$/