----------------------------------------
Subject: Re: [Haskell-beginners] making function problem (chapter 6 of Programming in Haskell) From: ds@iai.uni-bonn.de To: rwobben@hotmail.com CC: beginners@haskell.org Date: Tue, 9 Aug 2011 14:41:13 +0200
Hi Roelof,
On Tue, 2011-08-09 at 12:16 +0000, Roelof Wobben wrote:
oke.
I see it
unfortunately its still not true. Your example with the concrete numbers is right, and it captures the scheme well. But try to check your code with it. I'd like to say its typos, but its actually the same typos as you had for the actual main example, calculating the lists. Try to answer the questions I ask below and then use the answers for a correct definition (that is very similar to the recent one).
I'm going for this :
postivePower :: Int -> Int -> Int
PostivePower x 1 = 1 because when you multiply something by one is remains the same value.
Does this really return the value you want? Is 5 * 1 = 1 ?
PostivePower x y = x + postivePower x y
Do you really want to call positivePower with the same y again, or more concretely: Is 4 * 3 = 4 + (4 * 3)?, or should there be a "2" somewhere?
It should be 2 so it would then be postivepower x y = x + postivepower x (y-1) Roelof