Safe Haskell | None |
---|---|
Language | Haskell2010 |
Synopsis
- type Stream a = Coroutine a ()
- forEach :: forall a b (es :: Effects) r. (forall (e1 :: Effects). Coroutine a b e1 -> Eff (e1 :& es) r) -> (a -> Eff es b) -> Eff es r
- yieldToList :: forall a (es :: Effects) r. (forall (e1 :: Effects). Stream a e1 -> Eff (e1 :& es) r) -> Eff es ([a], r)
- yieldToReverseList :: forall a (es :: Effects) r. (forall (e :: Effects). Stream a e -> Eff (e :& es) r) -> Eff es ([a], r)
- enumerate :: forall (e2 :: Effects) (es :: Effects) a r. e2 :> es => (forall (e1 :: Effects). Stream a e1 -> Eff (e1 :& es) r) -> Stream (Int, a) e2 -> Eff es r
- enumerateFrom :: forall (e2 :: Effects) (es :: Effects) a r. e2 :> es => Int -> (forall (e1 :: Effects). Stream a e1 -> Eff (e1 :& es) r) -> Stream (Int, a) e2 -> Eff es r
- mapMaybe :: forall (e2 :: Effects) (es :: Effects) a b r. e2 :> es => (a -> Maybe b) -> (forall (e1 :: Effects). Stream a e1 -> Eff (e1 :& es) r) -> Stream b e2 -> Eff es r
- catMaybes :: forall (e2 :: Effects) (es :: Effects) a r. e2 :> es => (forall (e1 :: Effects). Stream (Maybe a) e1 -> Eff (e1 :& es) r) -> Stream a e2 -> Eff es r
- yield :: forall (e1 :: Effects) (es :: Effects) a. e1 :> es => Stream a e1 -> a -> Eff es ()
- inFoldable :: forall t (e1 :: Effects) (es :: Effects) a. (Foldable t, e1 :> es) => t a -> Stream a e1 -> Eff es ()
Handle
type Stream a = Coroutine a () Source #
A handle to a stream that yields values of type a
. It is
implemented as a handle to a coroutine that expects values of type
()
and then yields values of type a
.
Handlers
:: forall a b (es :: Effects) r. (forall (e1 :: Effects). Coroutine a b e1 -> Eff (e1 :& es) r) | |
-> (a -> Eff es b) | Apply this effectful function for each element of the coroutine |
-> Eff es r |
>>> runPureEff $ yieldToList $ \y -> do forEach (inFoldable [0 .. 3]) $ \i -> do yield y i yield y (i * 10) ([0, 0, 1, 10, 2, 20, 3, 30], ())
:: forall a (es :: Effects) r. (forall (e1 :: Effects). Stream a e1 -> Eff (e1 :& es) r) | |
-> Eff es ([a], r) | Yielded elements and final result |
>>> runPureEff $ yieldToList $ \y -> do yield y 1 yield y 2 yield y 100 ([1,2,100], ())
:: forall a (es :: Effects) r. (forall (e :: Effects). Stream a e -> Eff (e :& es) r) | |
-> Eff es ([a], r) | Yielded elements in reverse order, and final result |
This is more efficient than yieldToList
because it gathers the
elements into a stack in reverse order. yieldToList
then reverses
that stack.
>>> runPureEff $ yieldToReverseList $ \y -> do yield y 1 yield y 2 yield y 100 ([100,2,1], ())
:: forall (e2 :: Effects) (es :: Effects) a r. e2 :> es | |
=> (forall (e1 :: Effects). Stream a e1 -> Eff (e1 :& es) r) | ͘ |
-> Stream (Int, a) e2 | |
-> Eff es r |
Pair each element in the stream with an increasing index, starting from 0.
>>> runPureEff $ yieldToList $ enumerate (inFoldable ["A", "B", "C"]) ([(0, "A"), (1, "B"), (2, "C")], ())
:: forall (e2 :: Effects) (es :: Effects) a r. e2 :> es | |
=> Int | Initial value |
-> (forall (e1 :: Effects). Stream a e1 -> Eff (e1 :& es) r) | |
-> Stream (Int, a) e2 | |
-> Eff es r |
Pair each element in the stream with an increasing index, starting from an inital value.
>>> runPureEff $ yieldToList $ enumerateFrom1 (inFoldable ["A", "B", "C"]) ([(1, "A"), (2, "B"), (3, "C")], ())
:: forall (e2 :: Effects) (es :: Effects) a r. e2 :> es | |
=> (forall (e1 :: Effects). Stream (Maybe a) e1 -> Eff (e1 :& es) r) | Input stream |
-> Stream a e2 | |
-> Eff es r |
Remove Nothing
elements from a stream.