diff options
| 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/th | |
| 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/th')
| -rw-r--r-- | testsuite/tests/th/T11145.stderr | 9 | ||||
| -rw-r--r-- | testsuite/tests/th/T9692.hs | 2 |
2 files changed, 5 insertions, 6 deletions
diff --git a/testsuite/tests/th/T11145.stderr b/testsuite/tests/th/T11145.stderr index 731349d908..b8c4a1c6a8 100644 --- a/testsuite/tests/th/T11145.stderr +++ b/testsuite/tests/th/T11145.stderr @@ -1,8 +1,7 @@ T11145.hs:8:1: error: - • Data constructor ‘MkFuggle’ returns type ‘Fuggle - Int (Maybe Bool)’ - instead of an instance of its parent type ‘Fuggle - Int (Maybe (a, b))’ - • In the definition of data constructor ‘MkFuggle’ + • Couldn't match type ‘Bool’ with ‘(a0, b0)’ + Expected: Fuggle Int (Maybe (a0, b0)) + Actual: Fuggle Int (Maybe Bool) + • In the result type of data constructor ‘MkFuggle’ In the data instance declaration for ‘Fuggle’ diff --git a/testsuite/tests/th/T9692.hs b/testsuite/tests/th/T9692.hs index 7f44342604..5394bea021 100644 --- a/testsuite/tests/th/T9692.hs +++ b/testsuite/tests/th/T9692.hs @@ -12,7 +12,7 @@ class C a where data F a (b :: k) :: Type instance C Int where - data F Int x = FInt x + data F Int (x :: Type) = FInt x $( do info <- qReify (mkName "F") runIO $ putStrLn $ pprint info |