安装 pipes
$ cabal install pipes
Installed pipes-4.3.9
Prelude> import Pipes
Prelude Pipes> import qualified Pipes.Prelude as P
Prelude Pipes P>
Pipes
Pipes 是一个处理流的库。
Prelude Pipes P> runEffect $ P.stdinLn >-> P.takeWhile (/= "quit") >-> P.stdoutLn
Test
Test
Apple
Apple
quit
Prelude Pipes P>