This library provides a "
ListT done right implementation" that obeys the
Here is an example of how you build and consume
import List.Transformer import qualified System.IO stdin :: ListT IO String stdin = ListT (do eof <- System.IO.isEOF if eof then return Nil else do string <- getLine return (Cons string stdin) ) stdout :: ListT IO String -> IO () stdout strings = do s <- next strings case s of Nil -> return () Cons string strings' -> do putStrLn string stdout strings' main :: IO () main = stdout stdin
... and here's an example use of this library to print every natural number using a style resembling list comprehensions:
import List.Transformer main :: IO () main = runListT (do n <- select [0..] liftIO (print n) )
To learn more, read the tutorial.
stack tool and then run:
$ stack setup $ stack ghci list-transformer Prelude> import List.Transformer Prelude List.Transformer> runListT (do n <- select [0..]; liftIO (print n) ) 0 1 2 3 ...
This library is pretty small so I don't expect there to be breaking changes since there's not that much that could possibly change.
License (BSD 3-clause)
Copyright (c) 2016 Gabriel Gonzalez All rights reserved.
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