Extra ' in error output concerning promoted kinds

[goldfire]

When I try to compile the following code, a slightly erroneous error message is produced:

{-# LANGUAGE DataKinds #-}

foo :: 'False
foo = undefined

The error message is

Kind mis-match
Expected kind `ArgKind', but `False' has kind 'Bool
In the type signature for `foo': foo :: False

The problem is that the kind of 'False is reported as 'Bool. However, if you use a kind written 'Bool in a program, that program fails to compile. As I understand it, the only way to write the kind of 'False is Bool, without the initial tick.

[simonpj@…]

commit 6100eb449c613e003e6114e03f1408f0366a8dba

Author: Simon Peyton Jones <simonpj@microsoft.com>
Date:   Thu Apr 5 11:42:53 2012 +0100

    Fix Trac #5952, by changing the Outputable TyCon instance,
    so that it does not print a quote in front of a promoted
    TyCon in a Kind.
    
    I also systematically renamed
       PromotedTypeTyCon  -->   PromotedTyCon
       PromotedDataTyCon  -->   PromotedDataCon

 compiler/basicTypes/DataCon.lhs  |    2 +-
 compiler/simplCore/OccurAnal.lhs |    9 ++++---
 compiler/types/Kind.lhs          |    2 +-
 compiler/types/TyCon.lhs         |   48 +++++++++++++++++++------------------
 compiler/types/Type.lhs          |    2 +-
 5 files changed, 33 insertions(+), 30 deletions(-)

[simonpj]

Good point thank you. Turns out that the change is picked up by an existing regression test, so I won't add a new one.