Nested binding/matching

[andrewbaxter]

I'm not sure if that's the right way to describe it, but roughly something like

{?[state, year] := *hos{state:state, year:[year, true]}}

instead of

{?[state, year] := *hos{state:state, year:year_}, last(year_), year = first(year_)}

would be very convenient while working with tuples/validities.