Re: erreta, a couple of unimportant missing words :-(

Ahn Ki-yung wrote:

Simple Cat (revisitied)

\begin{code}

import IO

findM f [] = return Nothing findM f (x:xs) = do { v <- x; if f v then return (Just v) else findM f xs }

isLeft (Left _) = True isLeft _ = False

main = findM (isLeft) (hCat stdin) where hCat h = try (hGetLine h) : hCat h

\end{code}

This is my answer for the question of my own,

which is posted a couple

of days before.

There are mapM, filterM in the Haskell 98 Standard Library.

But why no findM there ?

As you can see from simple cat, it seems quite useful.

I think fildM should be added to the module Monad.

-- Ahn Ki-yung