ref: 1ffa8bd8f32394b7c972bf6d15d27007d22cf33c dir: /test/t.aeiouy/
/^[^aeiouy]*a[^aeiouy]*e[^aeiouy]*i[^aeiouy]*o[^aeiouy]*u[^aeiouy]*y[^aeiouy]*$/