[Haskell-beginners] A basic misunderstanding of how to program with IO

Thomas Davie tom.davie at gmail.com
Sat May 8 12:44:35 EDT 2010


On 8 May 2010, at 17:09, Ozgur Akgun wrote:

> I might have misunderstood you, but what about using the existing interact function: http://haskell.org/ghc/docs/6.12.1/html/libraries/base-4.2.0.0/Prelude.html#v:interact
> 
> And for your interact, since it is not in the IO monad, you cannot write such a function. [ don't tell him about the unsafePerformIO :) ]

Uh, interact absolutely *is* in the IO monad, and is totally implementable without unsafePerformIO, like this:

interact f = putStr =<< f <$> getContents

Bob
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.haskell.org/pipermail/beginners/attachments/20100508/d70fb13c/attachment.html


More information about the Beginners mailing list