diff --git a/simple-pipe.cabal b/simple-pipe.cabal --- a/simple-pipe.cabal +++ b/simple-pipe.cabal @@ -2,7 +2,7 @@ cabal-version: >= 1.8 name: simple-pipe -version: 0.0.0.0 +version: 0.0.0.1 stability: Experimental author: Yoshikuni Jujo maintainer: Yoshikuni Jujo @@ -87,11 +87,11 @@ source-repository this type: git location: git://github.com/YoshikuniJujo/forest.git - tag: simple-pipe-0.0.0.0 + tag: simple-pipe-0.0.0.1 library hs-source-dirs: src - exposed-modules: Data.Pipe + exposed-modules: Data.Pipe, Data.Pipe.List build-depends: base == 4.*, monad-control == 0.3.*, lifted-base == 0.2.*, monads-tf == 0.1.* diff --git a/src/Data/Pipe/List.hs b/src/Data/Pipe/List.hs new file mode 100644 --- /dev/null +++ b/src/Data/Pipe/List.hs @@ -0,0 +1,21 @@ +module Data.Pipe.List ( + fromList, + toList, + ) where + +import Control.Applicative +import Data.Pipe + +fromList :: Monad m => [a] -> Pipe () a m () +fromList [] = return () +fromList (x : xs) = yield x >> fromList xs + +-- | Consume all values from the stream and return as a list. +-- This will pull all values into memory. + +toList :: Monad m => Pipe a () m [a] +toList = do + mx <- await + case mx of + Just x -> (x :) <$> toList + _ -> return []