Well, Foo *is* an instance of Num, so a correct Haskell impl
should pick that instance always. Since you don't define the
fromInteger method in the instance decl, you get a runtime error.
I don't know what you expect the [Foo] and Foo - Int defaults
to do.
GHCi fails to put the correct default
On Mon, Dec 17, 2001 at 08:57:28AM -0800, Simon Peyton-Jones wrote:
Well, Foo *is* an instance of Num, so a correct Haskell impl
should pick that instance always.
I was looking at what the implementations would allow, the module wasn't
supposed to be useful.
Since you don't define the
