ref: 96c2be96e4beaac08d89af4dea8069d9ca1c4b09 dir: /test/t.aeiouy/
/^[^aeiouy]*a[^aeiouy]*e[^aeiouy]*i[^aeiouy]*o[^aeiouy]*u[^aeiouy]*y[^aeiouy]*$/