Data.Vinyl.Utils.Const

Operations on constant type records.

Documentation

cfmap :: (a -> b) -> Rec (Const a) rs -> Rec (Const b) rs

Map a function over a constant type record.

cpure :: Record rs => a -> Rec (Const a) rs

Extension of pure to constant type records.

capp :: Rec (Const (a -> b)) rs -> Rec (Const a) rs -> Rec (Const b) rs

Extension of (*) to constant type records.

rconst :: (Applicative f, RecApplicative rs) => f a -> f (Rec (Const a) rs)

constCommute :: Functor f => Const (f a) b -> Compose f (Const a) b

Commute a constant functor with another functor.

rtraverseconst :: Applicative f => Rec (Const (f a)) rs -> f (Rec (Const a) rs)

Distribute a functor over a constant type record.

class Record rs where

Create a dummy record parametrized by Proxy. The class is named Record to signify that every possible type list is its instance.

Methods

proxyRecord :: Rec Proxy rs

Instances

Record k ([] k)

Record k rs => Record k ((:) k r rs)