id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
1696	Confusing type signature	guest		"I was working with some buggy numerical code of mine, and I was having problems with some types involving exponentiation. My working hypothesis was that the problem involved using `(^)` with a numerical type I had defined - I had checked `(^)`'s type through :t and saw:
{{{
 (^) :: forall a b. (Integral b, Num a) => a -> b -> a
}}}
I immediately thought that I needed another type class declaration for my new type, and went haring off on that tangent for a long time. Eventually someone on #haskell pointed out to me that the *base* could be Num, but the power to which it was being raised had to be Integral and that my problems stemmed from going foo^(1/3), and that what I needed was more along the lines of foo**(1/3). 

My confusion stemmed from the variables - the forall declaration goes, in order, a-b, and the curried signature itself goes a-b as well, but the classes goes b-a! This apparently is for no particular reason, and so I think it'd be good if the signatures :t displayed could be a little more consistent and go a-b as well, so it'd be instead:
{{{
 (^) :: forall a b. (Num a, Integral b) => a -> b -> a
}}}
A small thing, perhaps, but it did trip me up."	bug	closed	low	_|_	Compiler (Type checker)	6.6.1	fixed			Unknown/Multiple	Unknown/Multiple	None/Unknown	Unknown