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| author | Krzysztof Gogolewski <krzysztof.gogolewski@tweag.io> | 2022-12-05 18:58:34 +0100 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2022-12-08 08:33:36 -0500 |
| commit | 7658cdd47198512b699492688f51fc8682d194cd (patch) | |
| tree | 90712444d737b5d892578619f4c2db485c9bc411 | |
| parent | 9ec76f61c880539114314fc3e4f96a4694f38ebe (diff) | |
| download | haskell-7658cdd47198512b699492688f51fc8682d194cd.tar.gz | |
Restore show (typeRep @[]) == "[]"
The Show instance for TypeRep [] has changed in 9.5 to output "List"
because the name of the type constructor changed.
This seems to be accidental and is inconsistent with TypeReps of saturated
lists, which are printed as e.g. "[Int]".
For now, I'm restoring the old behavior; in the future,
maybe we should show TypeReps without puns (List, Tuple, Type).
| -rw-r--r-- | libraries/base/Data/Typeable/Internal.hs | 2 | ||||
| -rw-r--r-- | testsuite/tests/typecheck/should_run/TestTypeableBinary.hs | 1 | ||||
| -rw-r--r-- | testsuite/tests/typecheck/should_run/TestTypeableBinary.stdout | 1 |
3 files changed, 4 insertions, 0 deletions
diff --git a/libraries/base/Data/Typeable/Internal.hs b/libraries/base/Data/Typeable/Internal.hs index 209324d585..51ee0f745e 100644 --- a/libraries/base/Data/Typeable/Internal.hs +++ b/libraries/base/Data/Typeable/Internal.hs @@ -836,6 +836,8 @@ instance Show (TypeRep (a :: k)) where showTypeable :: Int -> TypeRep (a :: k) -> ShowS showTypeable _ TrType = showChar '*' showTypeable _ rep + | isListTyCon tc, [] <- tys = + showString "[]" | isListTyCon tc, [ty] <- tys = showChar '[' . shows ty . showChar ']' diff --git a/testsuite/tests/typecheck/should_run/TestTypeableBinary.hs b/testsuite/tests/typecheck/should_run/TestTypeableBinary.hs index e427c13725..e09893d169 100644 --- a/testsuite/tests/typecheck/should_run/TestTypeableBinary.hs +++ b/testsuite/tests/typecheck/should_run/TestTypeableBinary.hs @@ -35,3 +35,4 @@ main = do testRoundtrip (typeRep :: TypeRep 5) testRoundtrip (typeRep :: TypeRep "hello world") testRoundtrip (typeRep :: TypeRep ('Just 5)) + testRoundtrip (typeRep :: TypeRep []) diff --git a/testsuite/tests/typecheck/should_run/TestTypeableBinary.stdout b/testsuite/tests/typecheck/should_run/TestTypeableBinary.stdout index 6ef72dfb83..159367efd8 100644 --- a/testsuite/tests/typecheck/should_run/TestTypeableBinary.stdout +++ b/testsuite/tests/typecheck/should_run/TestTypeableBinary.stdout @@ -13,3 +13,4 @@ good: Int -> Int good: 5 good: "hello world" good: 'Just Natural 5 +good: [] |