| Copyright | (C) 2017 Csongor Kiss |
|---|---|
| License | BSD3 |
| Maintainer | Csongor Kiss <kiss.csongor.kiss@gmail.com> |
| Stability | experimental |
| Portability | non-portable |
| Safe Haskell | Safe |
| Language | Haskell2010 |
Data.Generics.Sum.Typed
Contents
Description
Derive constructor-field-type-based prisms generically.
- class AsType a s where
Prisms
class AsType a s where Source #
Sums that have a constructor with a field of the given type.
Minimal complete definition
Methods
A prism that projects a constructor uniquely identifiable by the type of
its field. Compatible with the lens package's Prism type.
>>>dog ^? _Typed @DogJust (MkDog {name = "Shep", age = Age 3})>>>cat ^? _Typed @(Name, Age)Just ("Mog",Age 5)>>>dog ^? _Typed @Age... ... ... The type Animal contains multiple constructors whose fields are of type Age. ... The choice of constructor is thus ambiguous, could be any of: ... Duck ... Turtle ...
injectTyped :: a -> s Source #
Inject by type.
projectTyped :: s -> Maybe a Source #
Project by type.