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* Expunge #ifdef and #ifndef from the codebaseJohn Ericson2019-07-142-6/+6
| | | | | | | | These are unexploded minds as far as the linter is concerned. I don't want to hit in my MRs by mistake! I did this with `sed`, and then rolled back some changes in the docs, config.guess, and the linter itself.
* Improve doc for :type-at. (#14780)Roland Senn2019-06-271-1/+8
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* Add -Wmissing-safe-haskell-mode warningOleg Grenrus2019-06-251-1/+17
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* Add -Winferred-safe-imports warningOleg Grenrus2019-06-251-1/+34
| | | | | | | | | | | | | This commit partly reverts e69619e923e84ae61a6bb4357f06862264daa94b commit by reintroducing Sf_SafeInferred SafeHaskellMode. We preserve whether module was declared or inferred Safe. When declared-Safe module imports inferred-Safe, we warn. This inferred status is volatile, often enough it's a happy coincidence, something which cannot be relied upon. However, explicitly Safe or Trustworthy packages won't accidentally become Unsafe. Updates haddock submodule.
* Bump containers submodule to v0.6.2.1Ben Gamari2019-06-253-3/+3
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* Refactor UnliftedNewtypes-relation kind signature validity checksRyan Scott2019-06-231-16/+35
| | | | | | | | | | | | | | | | | | | | | This fixes three infelicities related to the programs that are (and aren't) accepted with `UnliftedNewtypes`: * Enabling `UnliftedNewtypes` would permit newtypes to have return kind `Id Type`, which had disastrous results (i.e., GHC panics). * Data family declarations ending in kind `TYPE r` (for some `r`) weren't being accepted if `UnliftedNewtypes` wasn't enabled, despite the GHC proposal specifying otherwise. * GHC wasn't warning about programs that _would_ typecheck if `UnliftedNewtypes` were enabled in certain common cases. As part of fixing these issues, I factored out the logic for checking all of the various properties about data type/data family return kinds into a single `checkDataKindSig` function. I also cleaned up some of the formatting in the existing error message that gets thrown. Fixes #16821, fixes #16827, and fixes #16829.
* Add HoleFitPlugins and RawHoleFitswip/D5373Matthías Páll Gissurarson2019-06-211-0/+323
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a new kind of plugin, Hole fit plugins. These plugins can change what candidates are considered when looking for valid hole fits, and add hole fits of their own. The type of a plugin is relatively simple, ``` type FitPlugin = TypedHole -> [HoleFit] -> TcM [HoleFit] type CandPlugin = TypedHole -> [HoleFitCandidate] -> TcM [HoleFitCandidate] data HoleFitPlugin = HoleFitPlugin { candPlugin :: CandPlugin , fitPlugin :: FitPlugin } data TypedHole = TyH { tyHRelevantCts :: Cts -- ^ Any relevant Cts to the hole , tyHImplics :: [Implication] -- ^ The nested implications of the hole with the -- innermost implication first. , tyHCt :: Maybe Ct -- ^ The hole constraint itself, if available. } This allows users and plugin writers to interact with the candidates and fits as they wish, even going as far as to allow them to reimplement the current functionality (since `TypedHole` contains all the relevant information). As an example, consider the following plugin: ``` module HolePlugin where import GhcPlugins import TcHoleErrors import Data.List (intersect, stripPrefix) import RdrName (importSpecModule) import TcRnTypes import System.Process plugin :: Plugin plugin = defaultPlugin { holeFitPlugin = hfp, pluginRecompile = purePlugin } hfp :: [CommandLineOption] -> Maybe HoleFitPluginR hfp opts = Just (fromPureHFPlugin $ HoleFitPlugin (candP opts) (fp opts)) toFilter :: Maybe String -> Maybe String toFilter = flip (>>=) (stripPrefix "_module_") replace :: Eq a => a -> a -> [a] -> [a] replace match repl str = replace' [] str where replace' sofar (x:xs) | x == match = replace' (repl:sofar) xs replace' sofar (x:xs) = replace' (x:sofar) xs replace' sofar [] = reverse sofar -- | This candidate plugin filters the candidates by module, -- using the name of the hole as module to search in candP :: [CommandLineOption] -> CandPlugin candP _ hole cands = do let he = case tyHCt hole of Just (CHoleCan _ h) -> Just (occNameString $ holeOcc h) _ -> Nothing case toFilter he of Just undscModName -> do let replaced = replace '_' '.' undscModName let res = filter (greNotInOpts [replaced]) cands return $ res _ -> return cands where greNotInOpts opts (GreHFCand gre) = not $ null $ intersect (inScopeVia gre) opts greNotInOpts _ _ = True inScopeVia = map (moduleNameString . importSpecModule) . gre_imp -- Yes, it's pretty hacky, but it is just an example :) searchHoogle :: String -> IO [String] searchHoogle ty = lines <$> (readProcess "hoogle" [(show ty)] []) fp :: [CommandLineOption] -> FitPlugin fp ("hoogle":[]) hole hfs = do dflags <- getDynFlags let tyString = showSDoc dflags . ppr . ctPred <$> tyHCt hole res <- case tyString of Just ty -> liftIO $ searchHoogle ty _ -> return [] return $ (take 2 $ map (RawHoleFit . text . ("Hoogle says: " ++)) res) ++ hfs fp _ _ hfs = return hfs ``` with this plugin available, you can compile the following file ``` {-# OPTIONS -fplugin=HolePlugin -fplugin-opt=HolePlugin:hoogle #-} module Main where import Prelude hiding (head, last) import Data.List (head, last) t :: [Int] -> Int t = _module_Prelude g :: [Int] -> Int g = _module_Data_List main :: IO () main = print $ t [1,2,3] ``` and get the following output: ``` Main.hs:14:5: error: • Found hole: _module_Prelude :: [Int] -> Int Or perhaps ‘_module_Prelude’ is mis-spelled, or not in scope • In the expression: _module_Prelude In an equation for ‘t’: t = _module_Prelude • Relevant bindings include t :: [Int] -> Int (bound at Main.hs:14:1) Valid hole fits include Hoogle says: GHC.List length :: [a] -> Int Hoogle says: GHC.OldList length :: [a] -> Int t :: [Int] -> Int (bound at Main.hs:14:1) g :: [Int] -> Int (bound at Main.hs:17:1) length :: forall (t :: * -> *) a. Foldable t => t a -> Int with length @[] @Int (imported from ‘Prelude’ at Main.hs:5:1-34 (and originally defined in ‘Data.Foldable’)) maximum :: forall (t :: * -> *) a. (Foldable t, Ord a) => t a -> a with maximum @[] @Int (imported from ‘Prelude’ at Main.hs:5:1-34 (and originally defined in ‘Data.Foldable’)) (Some hole fits suppressed; use -fmax-valid-hole-fits=N or -fno-max-valid-hole-fits) | 14 | t = _module_Prelude | ^^^^^^^^^^^^^^^ Main.hs:17:5: error: • Found hole: _module_Data_List :: [Int] -> Int Or perhaps ‘_module_Data_List’ is mis-spelled, or not in scope • In the expression: _module_Data_List In an equation for ‘g’: g = _module_Data_List • Relevant bindings include g :: [Int] -> Int (bound at Main.hs:17:1) Valid hole fits include Hoogle says: GHC.List length :: [a] -> Int Hoogle says: GHC.OldList length :: [a] -> Int g :: [Int] -> Int (bound at Main.hs:17:1) head :: forall a. [a] -> a with head @Int (imported from ‘Data.List’ at Main.hs:7:19-22 (and originally defined in ‘GHC.List’)) last :: forall a. [a] -> a with last @Int (imported from ‘Data.List’ at Main.hs:7:25-28 (and originally defined in ‘GHC.List’)) | 17 | g = _module_Data_List ``` This relatively simple plugin has two functions, as an example of what is possible to do with hole fit plugins. The candidate plugin starts by filtering the candidates considered by module, indicated by the name of the hole (`_module_Data_List`). The second function is in the fit plugin, where the plugin invokes a local hoogle instance to search by the type of the hole. By adding the `RawHoleFit` type, we can also allow these completely free suggestions, used in the plugin above to display fits found by Hoogle. Additionally, the `HoleFitPluginR` wrapper can be used for plugins to maintain state between invocations, which can be used to speed up invocation of plugins that have expensive initialization. ``` -- | HoleFitPluginR adds a TcRef to hole fit plugins so that plugins can -- track internal state. Note the existential quantification, ensuring that -- the state cannot be modified from outside the plugin. data HoleFitPluginR = forall s. HoleFitPluginR { hfPluginInit :: TcM (TcRef s) -- ^ Initializes the TcRef to be passed to the plugin , hfPluginRun :: TcRef s -> HoleFitPlugin -- ^ The function defining the plugin itself , hfPluginStop :: TcRef s -> TcM () -- ^ Cleanup of state, guaranteed to be called even on error } ``` Of course, the syntax here is up for debate, but hole fit plugins allow us to experiment relatively easily with ways to interact with typed-holes without having to dig deep into GHC. Reviewers: bgamari Subscribers: rwbarton, carter Differential Revision: https://phabricator.haskell.org/D5373
* users-guide: Update -Wsafe description for #16689Ben Gamari2019-06-191-1/+2
| | | | | We no longer emit a warning when a safe module is explicitly declared as such.
* users-guide: Fix a variety of broken links and syntaxBen Gamari2019-06-195-19/+30
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* Implement the -XUnliftedNewtypes extension.Andrew Martin2019-06-142-0/+98
| | | | | | | | | | | | | | | | | | | | | | | | | | | GHC Proposal: 0013-unlifted-newtypes.rst Discussion: https://github.com/ghc-proposals/ghc-proposals/pull/98 Issues: #15219, #1311, #13595, #15883 Implementation Details: Note [Implementation of UnliftedNewtypes] Note [Unifying data family kinds] Note [Compulsory newtype unfolding] This patch introduces the -XUnliftedNewtypes extension. When this extension is enabled, GHC drops the restriction that the field in a newtype must be of kind (TYPE 'LiftedRep). This allows types like Int# and ByteArray# to be used in a newtype. Additionally, coerce is made levity-polymorphic so that it can be used with newtypes over unlifted types. The bulk of the changes are in TcTyClsDecls.hs. With -XUnliftedNewtypes, getInitialKind is more liberal, introducing a unification variable to return the kind (TYPE r0) rather than just returning (TYPE 'LiftedRep). When kind-checking a data constructor with kcConDecl, we attempt to unify the kind of a newtype with the kind of its field's type. When typechecking a data declaration with tcTyClDecl, we again perform a unification. See the implementation note for more on this. Co-authored-by: Richard Eisenberg <rae@richarde.dev>
* users-guide: Fix a few markup issuesBen Gamari2019-06-132-23/+24
| | | | | | | Strangely these were only causing the build to fail in the aarch64-linux job, despite Sphinx throwing errors in all jobs I checked. Also changes some `#ifdef`s to `#if defined` to satisfy the linter.
* rts/RtsFlags.c: mention that -prof too enables support for +RTS -lAlp Mestanogullari2019-06-111-1/+1
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* Warn about unused packagesYuras Shumovich2019-06-112-0/+17
| | | | | | | | | | | | Reviewers: bgamari, simonpj Reviewed By: simonpj Subscribers: hvr, simonpj, mpickering, rwbarton, carter GHC Trac Issues: #15838 Differential Revision: https://phabricator.haskell.org/D5285
* Add disable/enable commands to ghci debugger #2215Roland Senn2019-06-092-9/+41
| | | | | | | | | | | | | | | | | | | | This patch adds two new commands `:enable` and `:disable` to the GHCi debugger. Opposite to `:set stop <n> :continue` a breakpoint disabled with `:disable` will not loose its previously set stop command. A new field breakEnabled is added to the BreakLocation data structure to track the enable/disable state. When a breakpoint is disabled with a `:disable` command, the following happens: The corresponding BreakLocation data element is searched dictionary of the `breaks` field of the GHCiStateMonad. If the break point is found and not already in the disabled state, the breakpoint is removed from bytecode. The BreakLocation data structure is kept in the breaks list and the new breakEnabled field is set to false. The `:enable` command works similar. The breaks field in the GHCiStateMonad was changed from an association list to int `IntMap`.
* Add HEAP_PROF_SAMPLE_END event to mark end of samplesMatthew Pickering2019-06-071-0/+8
| | | | | | | This allows a user to observe how long a sampling period lasts so that the time taken can be removed from the profiling output. Fixes #16697
* Add GHCi :instances commandXavier Denis2019-06-042-0/+37
| | | | | | | | | | | This commit adds the `:instances` command to ghci following proosal number 41. This makes it possible to query which instances are available to a given type. The output of this command is all the possible instances with type variables and constraints instantiated.
* Reject nested foralls in foreign imports (#16702)Ryan Scott2019-05-311-3/+23
| | | | | | | | This replaces a panic observed in #16702 with a simple error message stating that nested `forall`s simply aren't allowed in the type signature of a `foreign import` (at least, not at present). Fixes #16702.
* Eventlog: Document the fact timestamps are nanosecondsMatthew Pickering2019-05-311-0/+4
| | | | [skip ci]
* Fix some warnings in users_guide (incl #16640)Oleg Grenrus2019-05-293-3/+11
| | | | | | | | | | | | | | - short underline - :ghc-flag:, not :ghc-flags: - :since: have to be separate - newline before code block - workaround anchor generation so - pragma:SPECIALISE - pragma:SPECIALIZE-INLINE - pragma:SPECIALIZE-inline are different anchors, not all the same `pragma:SPECIALIZE`
* Remove stale 8.2.1-notesOleg Grenrus2019-05-291-527/+0
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* Minor spelling fixes to users guide.P.C. Shyamshankar2019-05-298-8/+8
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* Correct the large tuples section in user's guideJoshua Price2019-05-271-8/+8
| | | | Fixes #16644.
* Use HsTyPats in associated type family defaultsRyan Scott2019-05-222-13/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Associated type family default declarations behave strangely in a couple of ways: 1. If one tries to bind the type variables with an explicit `forall`, the `forall`'d part will simply be ignored. (#16110) 2. One cannot use visible kind application syntax on the left-hand sides of associated default equations, unlike every other form of type family equation. (#16356) Both of these issues have a common solution. Instead of using `LHsQTyVars` to represent the left-hand side arguments of an associated default equation, we instead use `HsTyPats`, which is what other forms of type family equations use. In particular, here are some highlights of this patch: * `FamEqn` is no longer parameterized by a `pats` type variable, as the `feqn_pats` field is now always `HsTyPats`. * The new design for `FamEqn` in chronicled in `Note [Type family instance declarations in HsSyn]`. * `TyFamDefltEqn` now becomes the same thing as `TyFamInstEqn`. This means that many of `TyFamDefltEqn`'s code paths can now reuse the code paths for `TyFamInstEqn`, resulting in substantial simplifications to various parts of the code dealing with associated type family defaults. Fixes #16110 and #16356.
* Have GHCi use object code for UnboxedTuples modules #15454Michael Sloan2019-05-222-5/+15
| | | | | | | | | | | | The idea is to automatically enable -fobject-code for modules that use UnboxedTuples, along with all the modules they depend on. When looking into how to solve this, I was pleased to find that there was already highly similar logic for enabling code generation when -fno-code is specified but TemplateHaskell is used. The state before this patch was that if you used unboxed tuples then you had to enable `-fobject-code` globally rather than on a per module basis.
* Allow for multiple linker instances. Fixes Haskell portion of #3372.Julian Leviston2019-05-211-0/+4
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* users-guide: Fix -rtsopts defaultKirill Elagin2019-05-211-1/+1
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* Include CPP preprocessor dependencies in -M outputDavid Eichmann2019-05-211-0/+14
| | | | Issue #16521
* users-guide: Fix directive errors on 8.10Takenobu Tani2019-05-211-2/+4
| | | | | | | | | | | The following sections are not displayed due to a directive error: * -Wunused-record-wildcards * -Wredundant-record-wildcards I changed the location of the `since` directive. [skip ci]
* Guard CUSKs behind a language pragmaVladislav Zavialov2019-05-141-0/+12
| | | | | | | | | | | | | | GHC Proposal #36 describes a transition plan away from CUSKs and to top-level kind signatures: 1. Introduce a new extension, -XCUSKs, on by default, that detects CUSKs as they currently exist. 2. We turn off the -XCUSKs extension in a few releases and remove it sometime thereafter. This patch implements phase 1 of this plan, introducing a new language extension to control whether CUSKs are enabled. When top-level kind signatures are implemented, we can transition to phase 2.
* Fix bugs and documentation for #13456Roland Senn2019-05-101-1/+4
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* Implement ImportQualifiedPostShayne Fletcher2019-05-081-0/+32
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* Fix #16603 by documenting some important changes in changelogsRyan Scott2019-05-081-0/+43
| | | | | | This addresses some glaring omissions from `libraries/base/changelog.md` and `docs/users_guide/8.8.1-notes.rst`, fixing #16603 in the process.
* Fix #16593 by having only one definition of -fprint-explicit-runtime-repsChaitanya Koparkar2019-05-052-23/+11
| | | | [skip ci]
* Fix typo in 8.8.1 notes related to traceBinaryEventiustin2019-05-041-2/+3
| | | | - fixes double mention of `traceBinaryEvent#` (the second one should be `traceEvent#`, I think) - fixes note about `traceEvent#` taking a `String` - the docs say it takes a zero-terminated ByteString.
* Make equality constraints in kinds invisibleRyan Scott2019-05-031-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Issues #12102 and #15872 revealed something strange about the way GHC handles equality constraints in kinds: it treats them as _visible_ arguments! This causes a litany of strange effects, from strange error messages (https://gitlab.haskell.org/ghc/ghc/issues/12102#note_169035) to bizarre `Eq#`-related things leaking through to GHCi output, even without any special flags enabled. This patch is an attempt to contain some of this strangeness. In particular: * In `TcHsType.etaExpandAlgTyCon`, we propagate through the `AnonArgFlag`s of any `Anon` binders. Previously, we were always hard-coding them to `VisArg`, which meant that invisible binders (like those whose kinds were equality constraint) would mistakenly get flagged as visible. * In `ToIface.toIfaceAppArgsX`, we previously assumed that the argument to a `FunTy` always corresponding to a `Required` argument. We now dispatch on the `FunTy`'s `AnonArgFlag` and map `VisArg` to `Required` and `InvisArg` to `Inferred`. As a consequence, the iface pretty-printer correctly recognizes that equality coercions are inferred arguments, and as a result, only displays them in `-fprint-explicit-kinds` is enabled. * Speaking of iface pretty-printing, `Anon InvisArg` binders were previously being pretty-printed like `T (a :: b ~ c)`, as if they were required. This seemed inconsistent with other invisible arguments (that are printed like `T @{d}`), so I decided to switch this to `T @{a :: b ~ c}`. Along the way, I also cleaned up a minor inaccuracy in the users' guide section for constraints in kinds that was spotted in https://gitlab.haskell.org/ghc/ghc/issues/12102#note_136220. Fixes #12102 and #15872.
* users-guide: Add libraries section to 8.10.1 release notesBen Gamari2019-04-211-0/+40
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* users-guide: Add pretty to package listBen Gamari2019-04-211-0/+1
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* TH: make `Lift` and `TExp` levity-polymorphicAlec Theriault2019-04-182-20/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Besides the obvious benefits of being able to manipulate `TExp`'s of unboxed types, this also simplified `-XDeriveLift` all while making it more capable. * `ghc-prim` is explicitly depended upon by `template-haskell` * The following TH things are parametrized over `RuntimeRep`: - `TExp(..)` - `unTypeQ` - `unsafeTExpCoerce` - `Lift(..)` * The following instances have been added to `Lift`: - `Int#`, `Word#`, `Float#`, `Double#`, `Char#`, `Addr#` - unboxed tuples of lifted types up to arity 7 - unboxed sums of lifted types up to arity 7 Ideally we would have levity-polymorphic _instances_ of unboxed tuples and sums. * The code generated by `-XDeriveLift` uses expression quotes instead of generating large amounts of TH code and having special hard-coded cases for some unboxed types.
* users-guide: document :set local-configFraser Tweedale2019-04-151-0/+17
| | | | | | | | Document the ':set local-config' command and add a warning about sourcing untrusted local .ghci scripts. Related: https://gitlab.haskell.org/ghc/ghc/issues/6017 Related: https://gitlab.haskell.org/ghc/ghc/issues/14250
* users-guide: update startup script orderFraser Tweedale2019-04-151-8/+8
| | | | | | | | Update users guide to match the new startup script order. Also clarify that -ignore-dot-ghci does not apply to scripts specified via the -ghci-script option. Part of: https://gitlab.haskell.org/ghc/ghc/issues/14689
* Apply suggestion to docs/users_guide/using-optimisation.rstGiles Anderson2019-04-151-1/+1
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* Document how -O3 is handled by GHCGiles Anderson2019-04-151-0/+11
| | | | | -O2 is the highest value of optimization. -O3 will be reverted to -O2.
* docs: mention memcpy optimization for ByteArrays in 8.10.1-notesArtem Pyanykh2019-04-141-4/+5
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* Add -ddump-stg-final to dump stg as it is used for codegen.klebinger.andreas@gmx.at2019-04-121-0/+5
| | | | | Intermediate STG does not contain free variables which can be useful sometimes. So adding a flag to dump that info.
* docs: add a note about changes in memset unrolling to 8.10.1-notesArtem Pyanykh2019-04-091-0/+5
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* users-guide: Document how to disable package environmentsBen Gamari2019-04-091-2/+8
| | | | As noted in #16309 this somehow went undocumented.
* Add `-optcxx` option (#16477)Yuriy Syrovetskiy2019-04-081-0/+7
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* Fix #16500: look for interface files in -hidir flag in OneShot modePhuong Trinh2019-04-081-0/+11
| | | | | | | | | | | We are currently ignoring options set in the hiDir field of hsc_dflags when looking for interface files while compiling in OneShot mode. This is inconsistent with the behaviour of other directory redirecting fields (such as objectDir or hieDir). It is also inconsistent with the behaviour of compilation in CompManager mode (a.k.a `ghc --make`) which looks for interface files in the directory set in hidir flag. This changes Finder.hs so that we use the value of hiDir while looking for interface in OneShot mode.
* Correct two misspellings of "separately"Chris Martin2019-04-031-1/+1
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* users-guide: Typo in Users Guide, Glasgow ExtsFrank Steffahn2019-04-031-1/+1
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