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| author | Vladislav Zavialov <vlad.z.4096@gmail.com> | 2018-06-14 15:02:36 -0400 |
|---|---|---|
| committer | Richard Eisenberg <rae@cs.brynmawr.edu> | 2018-06-14 15:05:32 -0400 |
| commit | d650729f9a0f3b6aa5e6ef2d5fba337f6f70fa60 (patch) | |
| tree | ac224609397d4b7ca7072fc87739d2522be7675b /compiler/deSugar/DsMeta.hs | |
| parent | 4672e2ebf040feffde4e7e2d79c479e4c0c3efaf (diff) | |
| download | haskell-d650729f9a0f3b6aa5e6ef2d5fba337f6f70fa60.tar.gz | |
Embrace -XTypeInType, add -XStarIsType
Summary:
Implement the "Embrace Type :: Type" GHC proposal,
.../ghc-proposals/blob/master/proposals/0020-no-type-in-type.rst
GHC 8.0 included a major change to GHC's type system: the Type :: Type
axiom. Though casual users were protected from this by hiding its
features behind the -XTypeInType extension, all programs written in GHC
8+ have the axiom behind the scenes. In order to preserve backward
compatibility, various legacy features were left unchanged. For example,
with -XDataKinds but not -XTypeInType, GADTs could not be used in types.
Now these restrictions are lifted and -XTypeInType becomes a redundant
flag that will be eventually deprecated.
* Incorporate the features currently in -XTypeInType into the
-XPolyKinds and -XDataKinds extensions.
* Introduce a new extension -XStarIsType to control how to parse * in
code and whether to print it in error messages.
Test Plan: Validate
Reviewers: goldfire, hvr, bgamari, alanz, simonpj
Reviewed By: goldfire, simonpj
Subscribers: rwbarton, thomie, mpickering, carter
GHC Trac Issues: #15195
Differential Revision: https://phabricator.haskell.org/D4748
Diffstat (limited to 'compiler/deSugar/DsMeta.hs')
| -rw-r--r-- | compiler/deSugar/DsMeta.hs | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/compiler/deSugar/DsMeta.hs b/compiler/deSugar/DsMeta.hs index 8ec181c430..1e85ea133e 100644 --- a/compiler/deSugar/DsMeta.hs +++ b/compiler/deSugar/DsMeta.hs @@ -288,10 +288,8 @@ and have Template Haskell turn it into this: idProxy :: forall k proxy (b :: k). proxy b -> proxy b idProxy x = x -Notice that we explicitly quantified the variable `k`! This is quite bad, as the -latter declaration requires -XTypeInType, while the former does not. Not to -mention that the latter declaration isn't even what the user wrote in the -first place. +Notice that we explicitly quantified the variable `k`! The latter declaration +isn't what the user wrote in the first place. Usually, the culprit behind these bugs is taking implicitly quantified type variables (often from the hsib_vars field of HsImplicitBinders) and putting @@ -1128,6 +1126,7 @@ repTy (HsEqTy _ t1 t2) = do t2' <- repLTy t2 eq <- repTequality repTapps eq [t1', t2'] +repTy (HsStarTy _ _) = repTStar repTy (HsKindSig _ t k) = do t1 <- repLTy t k1 <- repLTy k |