incorrect type error message

[Simon Peyton-Jones]

Your wish is my command

| > The reason there's an error message at all is because of the
| > monomorphism restriction.  So that's not surprising.
| > Can you suggest a better error message?  I'm always looking for ways
to
| > report errors more informatively.
| 
| It may be hard to do, but it would be helpful in cases like this for
| the error to mention the fact that the monomorphism restriction has
fired.
| Connecting the fact that the restriction has been applied and the
particular
| error may be a challenge. Just a thought.


	module Foo where
	e = fmap id 1

cam-02-unx:~/tmp$ $gpj -c Foo.hs

Foo.hs:5:
    No instance for (Num (f a))
      arising from the literal `1' at Foo.hs:5
    Probable cause: the monomorphism restriction applied to the
following:
      e :: f a (bound at Foo.hs:5)
    In the second argument of `fmap', namely `1'
    In a right-hand side of function `e': fmap id 1