Re: [Haskell-cafe] Fwd: Type families - how to resolve ambiguities?

2010-09-13 Thread Ryan Ingram
On Sun, Sep 12, 2010 at 9:24 AM, Dominique Devriese dominique.devri...@cs.kuleuven.be wrote: However, it would make more sense to have it be a type family, without the overhead of data (both in space and in typing). You can make Tensor a data family and use newtype instances. As I understand

Re: [Haskell-cafe] Fwd: Type families - how to resolve ambiguities?

2010-09-12 Thread Dominique Devriese
Paolo, The problem with mult is that k is not specified unambiguously. You either need v to determine k (which is probably not what you want, at a guess), mult to take a dummy argument that determines what k is: [...] or, to make Tensor a data family instead of a type family. What is the

[Haskell-cafe] Fwd: Type families - how to resolve ambiguities?

2010-09-11 Thread Paolo Giarrusso
On Aug 25, 11:22 pm, Dan Doel dan.d...@gmail.com wrote: On Wednesday 25 August 2010 5:05:11 pm DavidA wrote: The code below defines a type synonym family: {-# LANGUAGE MultiParamTypeClasses, TypeFamilies #-} {-# LANGUAGE FlexibleInstances, TypeSynonymInstances #-} [snip] The problem