HList-0.3.0: examples/lens.ref

"hi"
Record{x=(),y=Record{y=321,x=123}}
123
Record{x="hi",y=Record{y="xy",x=123}}


and repeat:
"hi"
Record{x=(),y=Record{y=321,x=123}}
321
Record{x="hi",y=Record{y="xy",x=123}}