[Haskell-beginners] factorial question

[Nick Vanderweit]

You probably don't want to use n+k patterns. Here is a clearer way to write 
it:

factorial' :: Int -> Int
factorial'  0 = 1
factorial'  n = n*factorial' (n-1)


Nick

On Friday, August 31, 2012 12:30:34 PM Brandon Allbery wrote:
> On Fri, Aug 31, 2012 at 12:23 PM, KMandPJLynch 
<kmandpjlynch at verizon.net>wrote:
> > *factorial'      :: Int -> Int*
> > *factorial'  0    = 1*
> > *factorial' (n+1) = (n+1)*factorial' n*
> 
> n+k patterns were removed from Haskell 2010.  You can re-enable them in GHC
> with
> 
> {-# LANGUAGE NPlusKPatterns #-}
> 
> or
> 
> {-# LANGUAGE Haskell98 #-}
> 
> as the first line of the source file.