#7368: kindFunResult panic in the
----------------------------------------+-----------------------------------
Reporter: ChrisN | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler (Type checker) | Version: 7.6.1
Keywords: Kinds, kindfunresult | Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time crash
Difficulty: Unknown | Testcase:
typecheck/should_fail/T7368
Blockedby: | Blocking:
Related: |
----------------------------------------+-----------------------------------
Comment(by simonpj@…):
commit be5cc2e33aa8e54299527af9b91e659d54c4cde5
{{{
Author: Simon Peyton Jones <simo...@microsoft.com>
Date: Wed Dec 19 23:49:47 2012 +0000
Fix TcUnify.matchExpectedTyConApp so that it returns types of
compatible kinds
This fixes Trac #7368. The problem was that we were matching
Bad w ~ f (Bad f)
where (f :: * -> *). Thta leads to (w ~ Bad f), which is
ill-kinded, but matchExpectedTyConApp was returning the (Bad f)
as the argument type, and that was being used to instanatiate
w in the data constructor type, which is very bad.
The code also becomes simpler and easier to understand, which is
an excellent thing.
compiler/typecheck/TcUnify.lhs | 81
++++++++++++++++++++--------------------
1 files changed, 40 insertions(+), 41 deletions(-)
}}}
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7368#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
_______________________________________________
Glasgow-haskell-bugs mailing list
Glasgow-haskell-bugs@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
