| Copyright | (C) 2020 Csongor Kiss |
|---|---|
| License | BSD3 |
| Maintainer | Csongor Kiss <kiss.csongor.kiss@gmail.com> |
| Stability | experimental |
| Portability | non-portable |
| Safe Haskell | None |
| Language | Haskell2010 |
Data.Generics.Sum.Typed
Contents
Description
Derive constructor-field-type-based prisms generically.
Synopsis
-
class
AsType
a s
where
- _Typed :: Prism' s a
- injectTyped :: a -> s
- projectTyped :: s -> Maybe a
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.
Instances
| AsType a Void Source # |
See Note [Uncluttering type signatures] >>> :t +d _Typed _Typed :: (AsType a s, Choice p, Applicative f) => p a (f a) -> p s (f s) |
|
Defined in Data.Generics.Sum.Typed |
|
| Context a s => AsType a s Source # | |
|
Defined in Data.Generics.Sum.Typed |
|
| AsType Void a Source # |
See Note [Uncluttering type signatures]
>>> :t +d _Typed
|
|
Defined in Data.Generics.Sum.Typed |
|