Re: [Haskell-cafe] IO in lists

16 Jan 2007


      Hi,

Am Dienstag, den 16.01.2007, 19:19 +0000 schrieb David House:
...
On 16/01/07, Yitzchak Gale  wrote:
...
listChars2 :: ListT IO Char
listChars2 = do
  c <- lift getChar
  if c == 'q'
    then return c
    else return c `mplus` listChars2
It's probably eaiser to work with normal lists:
listChars :: IO [Char]
listChars = do
  c <- getChar
  if c == 'q'
    then return c
    else liftM2 (:) (return c) listChars
But that is not lazy any more, is it? The idea of the OT was, I think,
that he can use the first elements of the list even before the last one
was entered.

Greetings,
Joachim

-- 
Joachim Breitner
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