Hi
I have some code that uses MPTC + FDs + flexible and undecidable
instances that was working fine until I did a trivial modification on
another part of the project. Now, GHC is complaining with a very
confusing (for me, at least) error message. I've been finally able to
reproduce the
I have a guess...
Daniel Gorín wrote:
Hi
I have some code that uses MPTC + FDs + flexible and undecidable
instances that was working fine until I did a trivial modification on
another part of the project. Now, GHC is complaining with a very
confusing (for me, at least) error message. I've
By the way, if you make the class C fundep declaration into:
class C m f n | m f - n where
then it compiles. This means ((M n) and (F n) imply N) and (any m and F'
imply N') which no longer conflict.
Daniel Gorín wrote:
Hi
I have some code that uses MPTC + FDs + flexible and undecidable
Hi, Chris
Thanks for your answer. I guess that my intuitions of what functional
dependencies and context meant were not very accurate (see below)
class C m f n | m - n, f - n where
c :: m - f - Bool
The m-n functional dependency means that I tell you
C x _ z is an instance then you
