| 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.Product.Positions
Contents
Description
Derive positional product type getters and setters generically.
- class HasPosition i a s | s i -> a where
Lenses
class HasPosition i a s | s i -> a where Source #
Records that have a field at a given position.
Minimal complete definition
Methods
position :: Lens' s a Source #
A lens that focuses on a field at a given position. Compatible with the
lens package's Lens type.
>>>human ^. position @1"Tunyasz">>>human & position @2 .~ "Berlin"Human {name = "Tunyasz", age = 50, address = "Berlin"}
getPosition :: s -> a Source #
Get positional field
>>>getPosition @1 human"Tunyasz"
setPosition :: a -> s -> s Source #
Set positional field
>>>setPosition @2 (setField @1 "Tamas" human) 30Human "Tamas" 30 "London"