On Mar 1, 11:23 pm, Marc 'BlackJack' Rintsch <[EMAIL PROTECTED]> wrote: (snip) > But the type of `x` must be specialized somehow. `x` doesn't start as > `Int` or `Integer` but the very generic and AFAIK abstract type class `Num`. > > After seeing the second line the compiler finds an implementation for `+` > and the type class `Fractional` for both operands and now thinks `x` must > be a `Fractional`, a subclass of `Num`. > > Then comes the third line with `length` returning an `Int` and the > `Fractional` `x` but there is no implementation for a `+` function on > those types.
I see, but the same arguments still holds true: the second line have an implicit side-effect of redefining x's type into Fractional type. If I were the designer of the language, I'd leave x's type as it is (as Num) and coerce x for current calculation only. -- http://mail.python.org/mailman/listinfo/python-list
