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| author | sheaf <sam.derbyshire@gmail.com> | 2021-10-15 23:09:39 +0200 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2021-10-17 14:06:46 -0400 |
| commit | 81740ce83976e9d6b68594f8a4b489452cca56e5 (patch) | |
| tree | 7b41d1529975c2f78eaced81e26e4722d34c212f /testsuite/tests/deriving/should_fail/T9687.stderr | |
| parent | 65bf3992aebb3c08f0c4e13a3fb89dd5620015a9 (diff) | |
| download | haskell-81740ce83976e9d6b68594f8a4b489452cca56e5.tar.gz | |
Introduce Concrete# for representation polymorphism checks
PHASE 1: we never rewrite Concrete# evidence.
This patch migrates all the representation polymorphism checks to
the typechecker, using a new constraint form
Concrete# :: forall k. k -> TupleRep '[]
Whenever a type `ty` must be representation-polymorphic
(e.g. it is the type of an argument to a function), we emit a new
`Concrete# ty` Wanted constraint. If this constraint goes
unsolved, we report a representation-polymorphism error to the user.
The 'FRROrigin' datatype keeps track of the context of the
representation-polymorphism check, for more informative error messages.
This paves the way for further improvements, such as
allowing type families in RuntimeReps and improving the soundness
of typed Template Haskell. This is left as future work (PHASE 2).
fixes #17907 #20277 #20330 #20423 #20426
updates haddock submodule
-------------------------
Metric Decrease:
T5642
-------------------------
Diffstat (limited to 'testsuite/tests/deriving/should_fail/T9687.stderr')
| -rw-r--r-- | testsuite/tests/deriving/should_fail/T9687.stderr | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/testsuite/tests/deriving/should_fail/T9687.stderr b/testsuite/tests/deriving/should_fail/T9687.stderr index 4c3dfe8255..fa6e04ff0a 100644 --- a/testsuite/tests/deriving/should_fail/T9687.stderr +++ b/testsuite/tests/deriving/should_fail/T9687.stderr @@ -1,5 +1,5 @@ T9687.hs:4:10: error: - • Class ‘Typeable’ does not support user-specified instances + • Class ‘Typeable’ does not support user-specified instances. • In the instance declaration for ‘Typeable (a, b, c, d, e, f, g, h)’ |