HeteroMap.Map

Documentation

data Key x a

A Key in a heterogeneous map. x is the key identifier type, which ensures that we don't look up a key in a map that doesn't have it.

newKey :: (forall x. Key x a -> b) -> b

Allocate a new key, which is only valid within the passed function (and will be a type error if it tries to escape).

data Map xs

A heterogeneous map, including keys xs.

empty :: Map ()

singleton :: Key x a -> a -> Map (x, ())

insert :: Key x a -> a -> Map xs -> Map (x, xs)

lookup :: In x xs => Key x a -> Map xs -> a

overwrite :: In x xs => Key x a -> a -> Map xs -> Map xs

Same as insert, except does not add the key identifier to the map, instead ensuring that it's already there.

union :: Map xs -> Map ys -> Map (Union xs ys)