constrained-some
Existential type that can be constrained
https://github.com/bruderj15/constrained-some
| Stackage Nightly 2026-07-30: | 0.1.3 |
| Latest on Hackage: | 0.1.3 |
Maintained by [email protected]
This version can be pinned in stack with:
constrained-some-0.1.3@sha256:e31166e69f3635a3e2348c3b9bfbdb522dc2aa3850135ff4bef09ba5f8576ecf,1464Module documentation for 0.1.3
- Data
- Data.Some
Depends on 1 package(full list with versions):
constrained-some
This library provides utilities for working with existential types and type-level constraints.
It allows you to enforce multiple constraints on polymorphic types and containers complementing some.
Core
- Existential types:
SomesandSomes1provide existential wrappers for types with multiple constraints. - Convenient aliases: Simplified types
SomeandSome1for scenarios where just one constraint is needed. - More convenient aliases: Simplified types
SomeFandSomesFfor scenarios where the container of aSomes1is known. - Natural transformations with constraints
mapSome :: (forall a. AllC csa a => f a -> g a) -> SomesF f csa -> SomesF g csatraverseSome :: Functor m => (forall a. AllC csa a => f a -> m (g a)) -> SomesF f csa -> m (SomesF g csa)
Usage
import Data.Some.Constraint
someShowableOrd :: Somes '[Show, Ord]
someShowableOrd = Some [1, 2, 3 :: Int]
someNumFunctor :: Some1 Functor Num
someNumFunctor = Some1 [1, 2, 3 :: Int]
someListShowable :: SomeF [] Show
someListShowable = Some1 [1, 2, 3 :: Int]
Contact information
Contributions, critics and bug reports are welcome!
Please feel free to contact me through GitHub.