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

[Ozgur Akgun]

On 8 May 2010 17:44, Thomas Davie <tom.davie at gmail.com> wrote:

>
> 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:
>
>
Upps now I need to clarify myself I guess.

I said "your interact is not in the IO monad", because the interact OP
defined had the type:

interact :: String -> Resp

Which obviously is not in the IO monad, if he is not hiding something in
Resp (looks unlikely to me)


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

And of course, interact is something implementable :)


Best,
Ozgur
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