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| author | Ryan Scott <ryan.gl.scott@gmail.com> | 2019-02-09 09:50:42 -0500 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2019-02-12 02:50:03 -0500 |
| commit | 012257c15f584069500af2953ab70856f9a1470e (patch) | |
| tree | e6822fee11572b3d04194da8c14b6e7f3794519d /compiler/types/Type.hs | |
| parent | 6399965d7f1636db6c777f597192467f93d800b1 (diff) | |
| download | haskell-012257c15f584069500af2953ab70856f9a1470e.tar.gz | |
Fix #16293 by cleaning up Proxy# infelicities
This bug fixes three problems related to `Proxy#`/`proxy#`:
1. Reifying it with TH claims that the `Proxy#` type constructor has
two arguments, but that ought to be one for consistency with
TH's treatment for other primitive type constructors like `(->)`.
This was fixed by just returning the number of
`tyConVisibleTyVars` instead of using `tyConArity` (which includes
invisible arguments).
2. The role of `Proxy#`'s visible argument was hard-coded as nominal.
Easily fixed by changing it to phantom.
3. The visibility of `proxy#`'s kind argument was specified, which
is different from the `Proxy` constructor (which treats it as
inferred). Some minor refactoring in `proxyHashId` fixed ths up.
Along the way, I had to introduce a `mkSpecForAllTy` function, so
I did some related Haddock cleanup in `Type`, where that function
lives.
Diffstat (limited to 'compiler/types/Type.hs')
| -rw-r--r-- | compiler/types/Type.hs | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/compiler/types/Type.hs b/compiler/types/Type.hs index e0ceb24b06..142da4c79c 100644 --- a/compiler/types/Type.hs +++ b/compiler/types/Type.hs @@ -36,7 +36,8 @@ module Type ( splitListTyConApp_maybe, repSplitTyConApp_maybe, - mkForAllTy, mkForAllTys, mkTyCoInvForAllTys, mkSpecForAllTys, + mkForAllTy, mkForAllTys, mkTyCoInvForAllTys, + mkSpecForAllTy, mkSpecForAllTys, mkVisForAllTys, mkTyCoInvForAllTy, mkInvForAllTy, mkInvForAllTys, splitForAllTys, splitForAllVarBndrs, @@ -1334,7 +1335,7 @@ interfaces. Notably this plays a role in tcTySigs in TcBinds.hs. ~~~~~~~~ -} --- | Make a dependent forall over an Inferred variablem +-- | Make a dependent forall over an 'Inferred' variable mkTyCoInvForAllTy :: TyCoVar -> Type -> Type mkTyCoInvForAllTy tv ty | isCoVar tv @@ -1343,13 +1344,13 @@ mkTyCoInvForAllTy tv ty | otherwise = ForAllTy (Bndr tv Inferred) ty --- | Like mkTyCoInvForAllTy, but tv should be a tyvar +-- | Like 'mkTyCoInvForAllTy', but tv should be a tyvar mkInvForAllTy :: TyVar -> Type -> Type mkInvForAllTy tv ty = ASSERT( isTyVar tv ) ForAllTy (Bndr tv Inferred) ty --- | Like mkForAllTys, but assumes all variables are dependent and Inferred, --- a common case +-- | Like 'mkForAllTys', but assumes all variables are dependent and +-- 'Inferred', a common case mkTyCoInvForAllTys :: [TyCoVar] -> Type -> Type mkTyCoInvForAllTys tvs ty = foldr mkTyCoInvForAllTy ty tvs @@ -1357,12 +1358,17 @@ mkTyCoInvForAllTys tvs ty = foldr mkTyCoInvForAllTy ty tvs mkInvForAllTys :: [TyVar] -> Type -> Type mkInvForAllTys tvs ty = foldr mkInvForAllTy ty tvs --- | Like mkForAllTys, but assumes all variables are dependent and Specified, +-- | Like 'mkForAllTy', but assumes the variable is dependent and 'Specified', -- a common case +mkSpecForAllTy :: TyVar -> Type -> Type +mkSpecForAllTy tv ty = ASSERT( isTyVar tv ) + -- covar is always Inferred, so input should be tyvar + ForAllTy (Bndr tv Specified) ty + +-- | Like 'mkForAllTys', but assumes all variables are dependent and +-- 'Specified', a common case mkSpecForAllTys :: [TyVar] -> Type -> Type -mkSpecForAllTys tvs = ASSERT( all isTyVar tvs ) - -- covar is always Inferred, so all inputs should be tyvar - mkForAllTys [ Bndr tv Specified | tv <- tvs ] +mkSpecForAllTys tvs ty = foldr mkSpecForAllTy ty tvs -- | Like mkForAllTys, but assumes all variables are dependent and visible mkVisForAllTys :: [TyVar] -> Type -> Type |