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| author | Ryan Scott <ryan.gl.scott@gmail.com> | 2017-09-02 15:33:25 -0400 |
|---|---|---|
| committer | Ryan Scott <ryan.gl.scott@gmail.com> | 2017-09-02 15:33:26 -0400 |
| commit | 8e4229ab3dc3e1717ad557ef00f3518da6b5c523 (patch) | |
| tree | 64a50dd06118a0d3709d37b258faa11eb4d1a218 /testsuite/tests/ghci/scripts/T7730.stdout | |
| parent | 5dd6b13c6e2942976aa3b5f4906ff7d0f959272d (diff) | |
| download | haskell-8e4229ab3dc3e1717ad557ef00f3518da6b5c523.tar.gz | |
Fix #14167 by using isGadtSyntaxTyCon in more places
Summary:
Two places in GHC effectively attempt to //guess// whether a data type
was declared using GADT syntax:
1. When reifying a data type in Template Haskell
2. When pretty-printing a data type (e.g., via `:info` in GHCi)
But there's no need for heuristics here, since we have a 100% accurate way to
determine whether a data type was declared using GADT syntax: the
`isGadtSyntaxTyCon` function! By simply using that as the metric, we obtain
far more accurate TH reification and pretty-printing results.
This is technically a breaking change, since Template Haskell reification will
now reify some data type constructors as `(Rec)GadtC` that it didn't before,
and some data type constructors that were previously reified as `(Rec)GadtC`
will no longer be reified as such. But it's a very understandable breaking
change, since the previous behavior was simply incorrect.
Test Plan: ./validate
Reviewers: simonpj, goldfire, austin, bgamari
Reviewed By: simonpj
Subscribers: rwbarton, thomie
GHC Trac Issues: #14167
Differential Revision: https://phabricator.haskell.org/D3901
Diffstat (limited to 'testsuite/tests/ghci/scripts/T7730.stdout')
| -rw-r--r-- | testsuite/tests/ghci/scripts/T7730.stdout | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/testsuite/tests/ghci/scripts/T7730.stdout b/testsuite/tests/ghci/scripts/T7730.stdout index e96e909413..bf9c1d025b 100644 --- a/testsuite/tests/ghci/scripts/T7730.stdout +++ b/testsuite/tests/ghci/scripts/T7730.stdout @@ -3,6 +3,5 @@ data A (x :: k) (y :: k1) -- Defined at <interactive>:2:1 A :: k1 -> k2 -> * type role T phantom -data T (a :: k) where - MkT :: forall k (a :: k) a1. a1 -> T a +data T (a :: k) = forall a1. MkT a1 -- Defined at <interactive>:6:1 |