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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2020-12-02 10:27:47 +0000 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-12-08 15:31:41 -0500 |
| commit | 62ed6957463a9c0f711ea698d7ed4371e00fb122 (patch) | |
| tree | eb13107435b357117fda5e787ce4a70bd111a8f8 /testsuite/tests/polykinds | |
| parent | 8fac4b9333ef3607e75b4520d847054316cb8c2d (diff) | |
| download | haskell-62ed6957463a9c0f711ea698d7ed4371e00fb122.tar.gz | |
Fix kind inference for data types. Again.
This patch fixes several aspects of kind inference for data type
declarations, especially data /instance/ declarations
Specifically
1. In kcConDecls/kcConDecl make it clear that the tc_res_kind argument
is only used in the H98 case; and in that case there is no result
kind signature; and hence no need for the disgusting splitPiTys in
kcConDecls (now thankfully gone).
The GADT case is a bit different to before, and much nicer.
This is what fixes #18891.
See Note [kcConDecls: kind-checking data type decls]
2. Do not look at the constructor decls of a data/newtype instance
in tcDataFamInstanceHeader. See GHC.Tc.TyCl.Instance
Note [Kind inference for data family instances]. This was a
new realisation that arose when doing (1)
This causes a few knock-on effects in the tests suite, because
we require more information than before in the instance /header/.
New user-manual material about this in "Kind inference in data type
declarations" and "Kind inference for data/newtype instance
declarations".
3. Minor improvement in kcTyClDecl, combining GADT and H98 cases
4. Fix #14111 and #8707 by allowing the header of a data instance
to affect kind inferece for the the data constructor signatures;
as described at length in Note [GADT return types] in GHC.Tc.TyCl
This led to a modest refactoring of the arguments (and argument
order) of tcConDecl/tcConDecls.
5. Fix #19000 by inverting the sense of the test in new_locs
in GHC.Tc.Solver.Canonical.canDecomposableTyConAppOK.
Diffstat (limited to 'testsuite/tests/polykinds')
| -rw-r--r-- | testsuite/tests/polykinds/T13659.stderr | 8 | ||||
| -rw-r--r-- | testsuite/tests/polykinds/T16221a.stderr | 4 |
2 files changed, 6 insertions, 6 deletions
diff --git a/testsuite/tests/polykinds/T13659.stderr b/testsuite/tests/polykinds/T13659.stderr index 84e81d04c0..dad726be5f 100644 --- a/testsuite/tests/polykinds/T13659.stderr +++ b/testsuite/tests/polykinds/T13659.stderr @@ -1,6 +1,6 @@ -T13659.hs:14:27: error: - • Expected a type, but ‘a’ has kind ‘[*]’ - • In the first argument of ‘Format’, namely ‘'[Int, a]’ - In the type ‘Format '[Int, a]’ +T13659.hs:14:15: error: + • Expected kind ‘[*]’, but ‘a’ has kind ‘*’ + • In the first argument of ‘Format’, namely ‘a’ + In the type ‘Format a’ In the definition of data constructor ‘I’ diff --git a/testsuite/tests/polykinds/T16221a.stderr b/testsuite/tests/polykinds/T16221a.stderr index 5aa099b0f1..5945369a6c 100644 --- a/testsuite/tests/polykinds/T16221a.stderr +++ b/testsuite/tests/polykinds/T16221a.stderr @@ -1,7 +1,7 @@ T16221a.hs:6:49: error: - • Expected kind ‘k’, but ‘b’ has kind ‘k1’ - ‘k1’ is a rigid type variable bound by + • Expected kind ‘k’, but ‘b’ has kind ‘k2’ + ‘k2’ is a rigid type variable bound by an explicit forall k (b :: k) at T16221a.hs:6:20 ‘k’ is a rigid type variable bound by |