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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2014-05-23 07:47:17 +0100 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2014-05-23 07:49:13 +0100 |
| commit | d8d97113c24e7216be36c9cdfc58e91f26528f06 (patch) | |
| tree | d1bf8d2c7ead0d63dbefd36dbecb2143905e8802 /testsuite/tests/polykinds/T9106.stderr | |
| parent | bc58d2e8a9da7cab90e4a06c28197d1d746a06cf (diff) | |
| download | haskell-d8d97113c24e7216be36c9cdfc58e91f26528f06.tar.gz | |
Make the unifier a fixpoint even for the free kind vars of a tyvar
The (pure) unifier tcUnifyTys returns an idempotent substitution.
But previously the kinds of type variables free in the range of
the subst could have un-substituted kind variables.
This patch fixes that, fixing Trac #9106.
See Note [Finding the substitution fixpoint] in Unify
Diffstat (limited to 'testsuite/tests/polykinds/T9106.stderr')
| -rw-r--r-- | testsuite/tests/polykinds/T9106.stderr | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/testsuite/tests/polykinds/T9106.stderr b/testsuite/tests/polykinds/T9106.stderr new file mode 100644 index 0000000000..0b239f2ea4 --- /dev/null +++ b/testsuite/tests/polykinds/T9106.stderr @@ -0,0 +1,8 @@ + +T9106.hs:13:10: + Illegal instance declaration for ‘FunctorN n f a (f fa)’ + The liberal coverage condition fails in class ‘FunctorN’ + for functional dependency: ‘n f a -> fa’ + Reason: lhs types ‘n’, ‘f’, ‘a’ + do not jointly determine rhs type ‘f fa’ + In the instance declaration for ‘FunctorN n f a (f fa)’ |