﻿id summary reporter owner description type status priority
milestone component version resolution keywords cc os
architecture failure difficulty testcase blockedby blocking
related 7220 Confusing error message in type checking related to
type family, fundep, and higher-rank type tsuyoshi simonpj
"(This is related to, but different from, the message which I
posted to glasgow-haskell-users mailing list:
http://www.haskell.org/pipermail/glasgow-haskell-
users/2012-September/022815.html.) GHC 7.6.1-rc1 (; 64-bit
Windows) rejects the attached code (Test2.hs) with the following
error message: {{{ Test2.hs:24:52: Couldn't match expected type
`Y' with actual type `TF (forall b. (C A b, TF b ~ Y) => b)' In
the first argument of `f :: (forall b. (C A b, TF b ~ Y) => b)
-> X', namely `u' In the expression: (f :: (forall b. (C A b, TF
b ~ Y) => b) -> X) u In an equation for `v': v = (f :: (forall
b. (C A b, TF b ~ Y) => b) -> X) u }}} I am not sure whether the
code is supposed to be accepted or rejected, but even if it i