Data.TypeMap.Static

Documentation

type family Index (a :: k) (d :: [(k, *)]) where ...

Index of type key a in association list d.

Equations

Index a ('(a, _) ': _) = 0

Index a (_ ': d) = 1 + Index a d

type family Lookup (a :: k) (d :: [(k, *)]) where ...

Type associated with a in d. If the key a occurs multiple times, the first one is used.

Equations

Lookup a ('(a, b) ': _) = b

Lookup a (_ ': d) = Lookup a d

type family Last (d :: [k]) where ...

Last element of a list.

Equations

Last (x ': '[]) = x

Last (_ ': d) = Last d

type family Init (d :: [k]) where ...

All elements except the last one.

Equations

Init (_ ': '[]) = '[]

Init (x ': d) = x ': Init d