Safe Haskell | Safe |
---|---|

Language | Haskell2010 |

## Synopsis

- interleave :: forall a m. (Monad m, Ord a) => [Producer a m ()] -> Producer a m ()
- combine :: (Monad m, Eq a) => (a -> a -> a) -> Producer a m r -> Producer a m r
- combineM :: (Monad m, Eq a) => (a -> a -> m a) -> Producer a m r -> Producer a m r
- merge :: (Monad m, Ord a) => (a -> a -> a) -> [Producer a m ()] -> Producer a m ()
- mergeM :: (Monad m, Ord a) => (a -> a -> m a) -> [Producer a m ()] -> Producer a m ()
- groupBy :: forall a r m. (Monad m, Ord a) => Producer a m r -> Producer [a] m r

# Documentation

Interleave elements from a set of `Producers`

such that the interleaved
stream is increasing with respect to the given ordering.

`>>>`

[1,1,3,5,5,7,9,9,13,17]`toList $ interleave [each [1,3..10], each [1,5..20]]`

Given a stream of increasing elements, combine those that are equal.

`>>>`

`let append (Entry k v) (Entry _ v') = Entry k (v+v')`

`>>>`

[Entry {priority = 1, payload = 5},Entry {priority = 2, payload = 3},Entry {priority = 3, payload = 10}]`toList $ combine append (each $ map (uncurry Entry) [(1,1), (1,4), (2,3), (3,10)])`

`combine`

with monadic side-effects in the combine operation.

:: (Monad m, Ord a) | |

=> (a -> a -> a) | combine operation |

-> [Producer a m ()] | producers of elements |

-> Producer a m () |

Equivalent to `combine`

composed with `interleave`

`>>>`

`let append (Entry k v) (Entry _ v') = Entry k (v+v')`

`>>>`

`let producers = [ each [Entry i 2 | i <- [1,3..10]], each [Entry i 10 | i <- [1,5..20]] ] :: [Producer (Entry Int Int) Identity ()]`

`>>>`

[(1,12),(3,2),(5,12),(7,2),(9,12),(13,10),(17,10)]`toList $ merge append producers`

:: (Monad m, Ord a) | |

=> (a -> a -> m a) | combine operation |

-> [Producer a m ()] | producers of elements |

-> Producer a m () |

Merge with monadic side-effects in the combine operation.

groupBy :: forall a r m. (Monad m, Ord a) => Producer a m r -> Producer [a] m r Source #

Split stream into groups of equal elements.
Note that this is a non-local operation: if the `Producer`

generates
a large run of equal elements, all of them will remain in memory until the
run ends.

`>>>`

[[Entry {priority = 1, payload = 1},Entry {priority = 1, payload = 4}],[Entry {priority = 2, payload = 3}],[Entry {priority = 3, payload = 10}]]`toList $ groupBy (each [Entry 1 1, Entry 1 4, Entry 2 3, Entry 3 10])`