Copyright	(c) Marcin Mrotek, 2014
License	BSD3
Maintainer	marcin.jan.mrotek@gmail.com
Safe Haskell	None
Language	Haskell2010
Extensions	UndecidableInstances MonoLocalBinds ScopedTypeVariables TypeFamilies PolyKinds DataKinds TypeSynonymInstances FlexibleContexts FlexibleInstances MultiParamTypeClasses KindSignatures TypeOperators ExplicitNamespaces ExplicitForAll

Data.Vinyl.Upcast

Description

Synopsis

Documentation

class Overwrite xs ys where Source

Overwrite a wider record with a narrower record.

Methods

overwrite :: Rec el f xs -> Rec el f ys -> Rec el f xs Source

Instances

Overwrite k xs ([] k)
(IElem k y xs, Overwrite k xs ys) => Overwrite k xs ((:) k y ys)

slice :: (Functor f, Overwrite xs ys, xs <: ys) => (Rec el g ys -> f (Rec el g ys)) -> Rec el g xs -> f (Rec el g xs) Source

A lens from a record to a portion of it.

class (Overwrite ys xs, ys <: xs) => xs :> ys where Source

Upward record casting.

Methods

upcast :: Monoid (AltRec el f ys) => Rec el f xs -> Rec el f ys Source

Instances

(Overwrite k ys xs, (<:) k ys xs) => (:>) k xs ys

newtype AltRec el f rs Source

Wrapper for Rec with a different Monoid instance. Instead of lifting mappend, it acts on (f (el $ r)) directly, to support temporarily turning records into monoids by changing functors.

Constructors

AltRec
Fields getRec :: Rec el f rs

Instances

(Monoid (f (($) * k el r)), Monoid (AltRec k el f rs)) => Monoid (AltRec k el f ((:) k r rs))
Monoid (AltRec k el f ([] k))