The first and third work, but not the second. Why?
Michael
==
f :: String - IO ()
f s = do putStrLn s
{-
g :: [String] - IO ()
g l = do s - l
putStrLn s
-}
{-
h :: [Int] - [Int]
h l = do i - l
return (i+1)
-}
==
serialize2.hs:29:9:
Couldn't
On Fri, 2011-01-28 at 11:20 -0800, michael rice wrote:
The first and third work, but not the second. Why?
When you use a do block, it can be the syntactic sugar for whatever
monad you like; but you do have to make a choice. Your first example
had a do block for the IO monad. Your third example
Beware of ListT. It only works if your internal monad is commutative, which
IO is not. (Maybe would work, for example)
On Fri, Jan 28, 2011 at 2:41 PM, Chris Smith cdsm...@gmail.com wrote:
On Fri, 2011-01-28 at 11:20 -0800, michael rice wrote:
The first and third work, but not the second.
And by works, I mean, ListT is is a monad only if the internal monad is
commutative.
On Fri, Jan 28, 2011 at 2:46 PM, Daniel Peebles pumpkin...@gmail.comwrote:
Beware of ListT. It only works if your internal monad is commutative, which
IO is not. (Maybe would work, for example)
On Fri, Jan
So, my suspicions are confirmed.
Thanks, all.
Michael
--- On Fri, 1/28/11, Daniel Peebles pumpkin...@gmail.com wrote:
From: Daniel Peebles pumpkin...@gmail.com
Subject: Re: [Haskell-cafe] Merry monad mixup?
To: Chris Smith cdsm...@gmail.com
Cc: michael rice nowg...@yahoo.com, haskell cafe
