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<h3 style="margin-top: 20px; margin-bottom: 10px;">
Andrei Borzenkov pushed to branch wip/sand-witch/check-@-binders at <a href="https://gitlab.haskell.org/ghc/ghc">Glasgow Haskell Compiler / GHC</a>
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<h4 style="margin-top: 10px; margin-bottom: 10px;">
Commits:
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<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/816561b451dee83619f7f6546b20dc4049f26201">816561b4</a></strong>
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<span> by Andrei Borzenkov </span> <i> at 2023-08-19T18:06:38+04:00 </i>
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<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: "GitLab Mono", "JetBrains Mono", "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Parser, renamer, type checker for @a-binders (17594)
As a part of GHC Proposal 448 were introduced invisible
type patterns (@a-patterns) in functions and lambdas:
id1 :: a -> a
id1 @t x = x :: t
id2 :: a -> a
id2 = \ @t x -> x :: t
Was introduced new data type ArgPat and now Match stores it
instead of Pat. ArgPat has two constructors: VisPat for
common patterns and InvisPat for @-patterns.
Parsing is implemented in production argpat. Was introduced
ArgPatBuilder to help post process new patterns.
Renaming of ArgPat is implemented in rnArgPats function.
Type checking is a bit tricky due to eager scolemisation.
It's implemented in new functions tcTopSkolemiseExpPatTys,
tcSkolemiseScopedExpPatTys, and tcArgPats. For more information
about hack with collecting `ExpPatType`s see Note
[Type-checking invisible type patterns: check mode]
Type-checking is currently limited by check mode and -XNoDeepSubsumption.
Examples of new code:
id1 :: forall a. a -> a
id1 @t x = x :: t
id2 :: a -> a
id2 @t x = x :: t
id3 :: a -> a
id3 = \ @t x -> x
id_RankN :: (forall a. a -> a) -> a -> a
id_RankN @t f = f @t
id4 = id_RankN \ @t x -> x :: t
id_list :: [forall a. a -> a]
id_list = [\ @t x -> x]
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<h4 style="margin-top: 10px; margin-bottom: 10px;">
30 changed files:
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<a href="#06764eb0158306b83ab1998d18316392a51838c2">
compiler/GHC/Builtin/Names/TH.hs
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<a href="#cc97d81e7223ad4a3a5e801156ca632f9fa75654">
compiler/GHC/Hs/Expr.hs
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<a href="#9f00edfedb0f969865b049a78de3866545b4a60b">
compiler/GHC/Hs/Instances.hs
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<li class="file-stats">
<a href="#0bae7e7e67b5f9b6ba2a371f8917cf74423a0c6f">
compiler/GHC/Hs/Pat.hs
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<a href="#7a1af22e4c32b9aa6ec708d9d3788e1c4db5da9a">
compiler/GHC/Hs/Utils.hs
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<a href="#5855ff1d64fcadf28e7984964e69e35ff4de7f0a">
compiler/GHC/HsToCore/Arrows.hs
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<a href="#085703923f9c18f6ac9f926ac9a4c7c7e6d9d9ed">
compiler/GHC/HsToCore/Match.hs
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<a href="#950eaa7de202a2e915b5ff68a4cfd16e972ad359">
compiler/GHC/HsToCore/Pmc/Desugar.hs
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<a href="#3c19c0be465f9a28d7b69f89c55648080fcc37eb">
compiler/GHC/HsToCore/Quote.hs
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<a href="#aa160d2e15ce4b9872864040e449a60d09ad648f">
compiler/GHC/HsToCore/Ticks.hs
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<a href="#94864be2e2eb1959a038d5d903a6c784e5cfb32a">
compiler/GHC/HsToCore/Utils.hs
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<a href="#649144a78135a23cabfc90dd83c4aabf448eb6ab">
compiler/GHC/Iface/Ext/Ast.hs
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<a href="#bf951467d4a9aa443cb109cb4c84a2891945649b">
compiler/GHC/Parser.y
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<a href="#446cb12ca6cefaf1c6eb79b7db643632744263c7">
compiler/GHC/Parser/PostProcess.hs
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<a href="#211a448f1df996899df14cfbd91d498ffa77b8bd">
compiler/GHC/Parser/Types.hs
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<li class="file-stats">
<a href="#af762064d779f7308dd415966c974f27d14f9943">
compiler/GHC/Rename/Bind.hs
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<a href="#892acbb198a9095c917740d3c1297b56df4e3b7e">
compiler/GHC/Rename/HsType.hs
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<a href="#cfa41b5649933e5b12f7796e9d49b9dd6a0bc59f">
compiler/GHC/Rename/Pat.hs
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<a href="#939d24c1002dc322659c1f67c9f3d2db2ae31dd4">
compiler/GHC/Rename/Utils.hs
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<li class="file-stats">
<a href="#134bd468c04c1bc43429f10f08db3962e9c56a70">
compiler/GHC/Tc/Deriv/Functor.hs
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<a href="#3aa56839e36b2219f9ad54f5646ef3005da9c672">
compiler/GHC/Tc/Deriv/Generate.hs
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<a href="#1dd9c7a6bbc222c976a6ec1c4b772232ae60f7e5">
compiler/GHC/Tc/Errors/Ppr.hs
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<a href="#cdba811872892f235fe7059df1a6c538fba60816">
compiler/GHC/Tc/Errors/Types.hs
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<a href="#6a1f039ed7725eddef15dd5f4dc318a3434f26c9">
compiler/GHC/Tc/Gen/App.hs
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<a href="#71fa5eb3ba70e1d3a6181a226c2c227d42f1eb7d">
compiler/GHC/Tc/Gen/Arrow.hs
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<li class="file-stats">
<a href="#83f745d921da7adb739e81f83e1c07e723e4a789">
compiler/GHC/Tc/Gen/Bind.hs
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<li class="file-stats">
<a href="#902811828741e6bcd64702935bbb54edbbd070ef">
compiler/GHC/Tc/Gen/Expr.hs
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<li class="file-stats">
<a href="#3377164bfe9a1f1a8cfd588703ae1e0ea1e91cf9">
compiler/GHC/Tc/Gen/Match.hs
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<li class="file-stats">
<a href="#3ee8be814b6c6727880deab3772e6af922524bf0">
compiler/GHC/Tc/Gen/Pat.hs
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<li class="file-stats">
<a href="#5c0a7f8291c984f0fc06f59e7cf10dbecc11598b">
compiler/GHC/Tc/TyCl/PatSyn.hs
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The diff was not included because it is too large.
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