[Haskell-cafe] Re: Keys and Maps [Was: Re: I just don't get it (data structures and OO)]

apfelmus writes: [ .. lengthy discussion and implementation .. ]

As an example, we have

Just "Earth" == lookup (at "Milky Way" at "Sun") universe

assuming that

universe :: Data.Map String (Data.Map String String)

All this hard work for something that in a lesser language would be the unimpressive: universe["Milky Way"]["Sun"] ;-P -- G.