Data.Monoid.State

Documentation

newtype T s a

This resembles the pure State monad. However, State in transformers is a StateT and mtl is not Haskell 98.

I hope I have the more natural parameter order for evaluate in contrast to mtl and transformers. However, it is different from the parameter order of run.

Constructors

Cons

Fields

run :: s -> (a, s)

Instances

Functor (T s)

C (T s)

Monoid a => Monoid (T s a)

pure :: a -> T s a

evaluate :: s -> T s a -> a

execute :: s -> T s a -> s

put :: Monoid a => s -> T s a

modify :: Monoid a => (s -> s) -> T s a

mapFst :: (a -> c) -> (a, b) -> (c, b)