[Haskell-beginners] Re: Enforcing Monad Laws

[Jorden M]

On Mon, Jul 19, 2010 at 6:05 AM, Ozgur Akgun <ozgurakgun at gmail.com> wrote:
> On 4 July 2010 16:41, Jorden M <jrm8005 at gmail.com> wrote:
>>
>> On Sun, Jul 4, 2010 at 11:16 AM, Daniel Fischer
>> <daniel.is.fischer at web.de> wrote:
>> > On Sunday 04 July 2010 16:05:48, Jorden M wrote:
>> >> > Now that I've had a really short look at Axioms, I think the Haskell
>> >> > equivalent would be QuickCheck properties. After all, Axioms are not
>> >> > enforced by the compiler, their only effect is documentation.
>> >> > Granted,
>> >> > they
>> >>
>> >> Really? I thought they were.
>> >>
>> >
>> > I think that's not even possible in general.
>>
>> It would equate to solving the Halting Problem, I suppose.
>
> Nope, it would just take long (ok, very long) to compute. Halting problem is
> undecidable in general.
>

No, I think Daniel is right -- it is not possible in general. It's
essentially verifying the behavior of a program, which is how the
Halting Problem is framed. Here we're looking at something more
general than `is the behavior of this program such that it halts?'.