gistfile1.hs

fact :: (Integral a) => a -> a
fact f
	| f == 0 		= 1
	| otherwise 	= f*fact (f-1)

fac :: (Integral a) => a -> a
fac 0 = 1
fac n = n*fac(n-1)

Why don't you write the tailrecursive variant fact using direct pattern matching, too?

fact :: (Integral a) => a -> a
fact 0  = 1
fact f  = fact f*(f-1)

I was just experimenting with guards. :) I realise why it didn't work now, stupid typo. fact f_(f-1) should be f_fact (f-1). Whoops! Cheers though. :)

I thought that you were trying to create a tailrecursive variant. Like this:

fac :: (Integral a) => a -> a
fac n = tailFac n 1
    where tailFac 0 p = p
          tailFac n p = tailFac (n-1) (n*p)