[Haskell-cafe] chr/ord?

michael rice nowgate at yahoo.com
Fri May 1 06:40:41 EDT 2009

Thank you.

I assumed when I saw this:
"we could use Maybe's
mplus to define a function,
parent s = (mother s) `mplus` (father s)"

that mplus was *already* present in Maybe.


--- On Fri, 5/1/09, Neil Mitchell <ndmitchell at gmail.com> wrote:

From: Neil Mitchell <ndmitchell at gmail.com>
Subject: Re: [Haskell-cafe] chr/ord?
To: "michael rice" <nowgate at yahoo.com>
Cc: "haskell-cafe at haskell.org" <haskell-cafe at haskell.org>, "Anton van Straaten" <anton at appsolutions.com>
Date: Friday, May 1, 2009, 6:32 AM


> But I get this when I try to use it:
> sheep.hs:30:22: Not in scope: `mplus'
> [michael at localhost ~]$

You need to import Control.Monad. You can find answers to these sorts
of questions with Hoogle: http://haskell.org/hoogle/?hoogle=mplus



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