Control.Monad.Generator

A monad transformer for the creation of Lists. Similar to Python's generators.

import Control.Monad.Identity (Identity(..))
import Data.List.Class (toList)

hanoi 0 _ _ _ = return ()
hanoi n from to other = do
    hanoi (n-1) from other to
    yield (from, to)
    hanoi (n-1) other to from

> runIdentity . toList . generate $ hanoi 3 'A' 'B' 'C' :: [(Char, Char)]
[('A','B'),('A','C'),('B','C'),('A','B'),('C','A'),('C','B'),('A','B')]

Documentation

newtype GeneratorT v m a

A monad transformer to create Lists. generate transforms a "GeneratorT v m a" to a "ListT m a".

Constructors

GeneratorT

Fields

runGeneratorT :: ContT v (ListT m) a

Instances

MonadTrans (GeneratorT v)

Monad m => Monad (GeneratorT v m)

Monad m => Functor (GeneratorT v m)

Monad m => Applicative (GeneratorT v m)

MonadIO m => MonadIO (GeneratorT v m)

generate :: Monad m => GeneratorT v m () -> ListT m v

yield :: Monad m => v -> GeneratorT v m ()

breakGenerator :: Monad m => GeneratorT v m a