Re: Is it time to start deprecating FunDeps?

Comments see below. On Wed, May 1, 2013 at 11:13 AM, AntC wrote:

...

Martin Sulzmann writes:

(1) There's a mechanical way to translate FD programs with non-overlapping instances to TF (and of course vice versa).

Martin, no! no! no! You have completely mis-understood.

I do _not_ _not_ _not_ want to replace FD's with TF's.

I want to replace FD's with Equality Constraints.

Ok, that's the bit I've missed, but then I argue that you can't fully encode FDs. Consider again the 'Sum' example. In the FD world: Sum x y z1, Sum x y z2 ==> z1 ~ z2 enforced by Sum x y z | x y -> z In my TF encoding, we find a similar derivation step SumF1 x y ~ z1, SumF1 x y ~ z2 ==> z1 ~ z2 So, you're asking can we translate/express FDs using GHC intermediate language with plain type equations only? -Martin

And that's exactly because I want to use overlapping.

(You've also failed to understand that the Sum example is for doing Peano Arith. See the solution I've just posted.)

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