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author | sheaf <sam.derbyshire@gmail.com> | 2021-10-15 23:09:39 +0200 |
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committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2021-10-17 14:06:46 -0400 |
commit | 81740ce83976e9d6b68594f8a4b489452cca56e5 (patch) | |
tree | 7b41d1529975c2f78eaced81e26e4722d34c212f /compiler/Language/Haskell/Syntax | |
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 'compiler/Language/Haskell/Syntax')
-rw-r--r-- | compiler/Language/Haskell/Syntax/Expr.hs | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/compiler/Language/Haskell/Syntax/Expr.hs b/compiler/Language/Haskell/Syntax/Expr.hs index 2215ed1210..e8538dfa43 100644 --- a/compiler/Language/Haskell/Syntax/Expr.hs +++ b/compiler/Language/Haskell/Syntax/Expr.hs @@ -973,10 +973,17 @@ data HsCmd id -- in Language.Haskell.Syntax.Extension --- | Haskell Array Application Type -data HsArrAppType = HsHigherOrderApp | HsFirstOrderApp - deriving Data - +-- | Haskell arrow application type. +data HsArrAppType + -- | First order arrow application '-<' + = HsHigherOrderApp + -- | Higher order arrow application '-<<' + | HsFirstOrderApp + deriving Data + +pprHsArrType :: HsArrAppType -> SDoc +pprHsArrType HsHigherOrderApp = text "higher order arrow application" +pprHsArrType HsFirstOrderApp = text "first order arrow application" {- | Top-level command, introducing a new arrow. This may occur inside a proc (where the stack is empty) or as an |