| Safe Haskell | Safe-Inferred |
|---|---|
| Language | Haskell2010 |
Frames.TypeLevel
Description
Helpers for working with type-level lists.
Synopsis
- type family AllAre (a :: k) (ts :: [k]) where ...
- type family ReplaceAll (a2 :: a) (xs :: [a1]) :: [a] where ...
- type family ReplaceAllSnd (a :: k) (xs :: [(k1, k2)]) :: [(k1, k)] where ...
Documentation
type family AllAre (a :: k) (ts :: [k]) where ... Source #
Constraint that every element of a promoted list is equal to a particular type. That is, the list of types is a single type repeated some number of times.
type family ReplaceAll (a2 :: a) (xs :: [a1]) :: [a] where ... Source #
ReplaceAll x ys produces a type-level list of the same length
as ys where each element is x. In other words, it replaces each
element of ys with x. This would be map (const x) ys in
value-level Haskell.
Equations
| ReplaceAll (a3 :: a1) ('[] :: [a2]) = '[] :: [a1] | |
| ReplaceAll (a3 :: a1) (x ': xs :: [a2]) = a3 ': ReplaceAll a3 xs |
type family ReplaceAllSnd (a :: k) (xs :: [(k1, k2)]) :: [(k1, k)] where ... Source #
Replace the second component of every tuple in a type-level list with a constant.
Equations
| ReplaceAllSnd (a :: k) ('[] :: [(k1, k2)]) = '[] :: [(k1, k)] | |
| ReplaceAllSnd (a :: k) ('(s, x) ': xs :: [(k1, k2)]) = '(s, a) ': ReplaceAllSnd a xs |