Hello,
I have some code like this (the contents don't really matter):
42 data TestChain next = ChainEntry (forall b . TestG b) next
43 | ChainDescribe String (Free TestChain...
44 deriving (Functor)
45
46 -- deriving instance Show a => Show (TestChain a)
47
48 it :: (SomeT typ, Partition t typ) => String -> t -> ...
49 it desc test = liftF (ChainEntry (mkTestG test) ())
And get the error:
Clean.hs:49:43:
Could not deduce (t ~ b)
from the context (SomeT typ, Partition t typ)
bound by the type signature for
it :: (SomeT typ, Partition t typ) =>
String -> t -> Free TestChain ()
at Clean.hs:49:1-51
`t' is a rigid type variable bound by
the type signature for
it :: (SomeT typ, Partition t typ) =>
String -> t -> Free TestChain ()
at Clean.hs:49:1
`b' is a rigid type variable bound by
a type expected by the context: TestG b at Clean.hs:49:23
[...]
In that last error line, should that not be "Clean.hs:42:..." (as it
references the 'b', which I only really have there), or is that
intended, and if yes, why?
I'm using GHC 7.4.2.
Thanks
Niklas
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