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[GHC] #9478: Partial type signatures
by GHC 10 May '16

10 May '16

#9478: Partial type signatures -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: | Differential Revisions: Phab:D168 -------------------------------------+------------------------------------- This ticket tracks progress on '''partial type signatures'''. * Wiki page [wiki:PartialTypeSignatures] * Phabricator link: Phab:D168 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9478> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4012: Compilation results are not deterministic
by GHC 10 May '16

10 May '16

#4012: Compilation results are not deterministic -------------------------------------+------------------------------------- Reporter: kili | Owner: niteria Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 6.12.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: 11362 | Blocking: Related Tickets: #10424 | Differential Rev(s): Phab:D910, | Phab:D1073, Phab:D1133, Phab:D1192, | Phab:D1268, Phab:D1360, Phab:D1373, Wiki Page: | Phab:D1396, Phab:D1457, Phab:D1468, DeterministicBuilds | Phab:D1487, Phab:D1504, Phab:D1508 -------------------------------------+------------------------------------- Comment (by Bartosz Nitka <niteria@…>): In [changeset:"b58b0e18a568bbf6381a85eea7adc72679355671/ghc" b58b0e1/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="b58b0e18a568bbf6381a85eea7adc72679355671" Make simplifyInstanceContexts deterministic simplifyInstanceContexts used cmpType which is nondeterministic for canonicalising typeclass constraints in derived instances. Following changes make it deterministic as explained by the Note [Deterministic simplifyInstanceContexts]. Test Plan: ./validate Reviewers: simonmar, goldfire, simonpj, austin, bgamari Reviewed By: simonpj Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2173 GHC Trac Issues: #4012 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4012#comment:160> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4012: Compilation results are not deterministic
by GHC 10 May '16

10 May '16

#4012: Compilation results are not deterministic -------------------------------------+------------------------------------- Reporter: kili | Owner: niteria Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 6.12.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: 11362 | Blocking: Related Tickets: #10424 | Differential Rev(s): Phab:D910, | Phab:D1073, Phab:D1133, Phab:D1192, | Phab:D1268, Phab:D1360, Phab:D1373, Wiki Page: | Phab:D1396, Phab:D1457, Phab:D1468, DeterministicBuilds | Phab:D1487, Phab:D1504, Phab:D1508 -------------------------------------+------------------------------------- Comment (by Bartosz Nitka <niteria@…>): In [changeset:"4ac0e815739f6362c2815dd3ae531055a095d6a9/ghc" 4ac0e81/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="4ac0e815739f6362c2815dd3ae531055a095d6a9" Kill unnecessary cmpType in lhs_cmp_type This is the only call site of `lhs_cmp_type` and we only care about equality. `cmpType` is nondeterministic (because `TyCon`s are compared with Uniques in `cmpTc`), so if we don't have to use it, it's better not to. Test Plan: ./validate Reviewers: simonmar, goldfire, bgamari, austin, simonpj Reviewed By: simonpj Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2172 GHC Trac Issues: #4012 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4012#comment:159> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11432: Cannot export operator newtype
by GHC 10 May '16

10 May '16

#11432: Cannot export operator newtype -------------------------------------+------------------------------------- Reporter: phadej | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs {-# LANGUAGE TypeOperators #-} module Main (main, (-.->)(..)) where main :: IO () main = return () newtype (f -.-> g) a = Fn { apFn :: f a -> g a } }}} Fails to compile with {{{ [1 of 1] Compiling Main ( fn.hs, interpreted ) fn.hs:2:20: error: Not in scope: ‘-.->’ fn.hs:2:20: error: The export item ‘(-.->)(..)’ attempts to export constructors or class methods that are not visible here }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11432> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11961: PatBind test suite failure with `-DDEBUG`
by GHC 10 May '16

10 May '16

#11961: PatBind test suite failure with `-DDEBUG` -------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 8.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I get {{{ Compile failed (status 256) errors were: ghc-stage2: panic! (the 'impossible' happened) (GHC version 8.1.20160420 for x86_64-unknown-linux): ASSERT failed! CallStack (from HasCallStack): assertPprPanic, called at compiler/types/TyCoRep.hs:2082:56 in ghc:TyCoRep checkValidSubst, called at compiler/types/TyCoRep.hs:2118:17 in ghc:TyCoRep substTy, called at compiler/types/TyCoRep.hs:2060:3 in ghc:TyCoRep in_scope InScope {a_apN t_apW a_apX} tenv [apC :-> t_apW[tau:3], apN :-> a_apX[tau:3]] tenvFVs [apD :-> t_apD[tau:3], apW :-> t_apW[tau:3], apX :-> a_apX[tau:3]] cenv [] cenvFVs [] tys [a_apN[sk] -> a_apN[sk]] cos [] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug *** unexpected failure for PatBind(normal) }}} with a `-DDEBUG` build, e.g. on travis: https://s3.amazonaws.com/archive .travis-ci.org/jobs/124426776/log.txt -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11961> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6118: Kind variable falls out of scope in instance declaration
by GHC 10 May '16

10 May '16

#6118: Kind variable falls out of scope in instance declaration -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.5 Resolution: fixed | Keywords: PolyKinds Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | polykinds/T6118 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Iceland_jack): 8.1.20160503: {{{#!hs -- twgv.hs:32:3-43: error: … -- The RHS of an associated type declaration mentions ‘k’ -- All such variables must be bound on the LHS -- Compilation failed. instance SingE (a :: Maybe k) where type Demote a = Maybe (Demote (Any :: k)) }}} Still fails, kind annotation needed: {{{#!hs instance SingE (a :: Maybe k) where type Demote (a ::Maybe k) = Maybe (Demote (Any :: k)) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6118#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7100: Loosen requirement for free variables in constraint in class declaration
by GHC 10 May '16

10 May '16

#7100: Loosen requirement for free variables in constraint in class declaration -------------------------------------+------------------------------------- Reporter: selinger | Owner: Type: feature request | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.4.2 Resolution: wontfix | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by Iceland_jack): * cc: Iceland_jack (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7100#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12027: ghc 8.0rc4 treats INLINE pragmas for methods with default (implicit) definitions as errors
by GHC 09 May '16

09 May '16

#12027: ghc 8.0rc4 treats INLINE pragmas for methods with default (implicit) definitions as errors -------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC rejects Unknown/Multiple | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I was getting around to testing some of my maths code with ghc 8.0 and i noticed that whereas in ghc 7.10 and earlier i could have an INLINE pragma for a method of a type class method that has a default implementation (whether this did anything or not is another question), in ghc 8.0 this now gives an ERROR (with not even a warning in ghc 7.10) is this a deliberate design change or an accident? I dont see it in the release notes! heres a small program that illustrates the differences (builds fine with no mention of the INLINE pragma matter under -Wall for 7.10, errors during build in 8.0) {{{ {-# LANGUAGE NoImplicitPrelude #-} module Main where import Prelude (putStrLn) import qualified Data.Functor as Fun import qualified Data.Foldable as F import Prelude hiding (map,foldl,foldr,init,scanl,scanr,scanl1,scanr1,foldl1,foldr1) newtype ListWrap a = ListWrap { unListWrap :: [a] } deriving (Eq, Show) instance Foldable ListWrap where {-# INLINE foldMap #-} {-# INLINE foldr #-} foldMap f (ListWrap ls)= (F.foldMap f ls ) main = putStrLn "hello" }}} this may be a *valid* design change, but i've not seen it documented anywhere, such as the release notes in the RC or in https://ghc.haskell.org/trac/ghc/wiki/Migration/8.0 ... so i'm assuming its a regression pending dicussion ;) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12027> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11802: Make a Win32 release
by GHC 08 May '16

08 May '16

#11802: Make a Win32 release -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: task | Status: new Priority: high | Milestone: 8.0.1 Component: Compiler | Version: 8.0.1-rc3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11802> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11692: Suggest default definition of Applicative
by GHC 08 May '16

08 May '16

#11692: Suggest default definition of Applicative -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: GHCi | Version: 8.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect Unknown/Multiple | warning at compile-time Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs ghci> data A a = A a deriving (Show, Functor) ghci> instance Monad A <interactive>:3:10: error: • No instance for (Applicative A) arising from the superclasses of an instance declaration • In the instance declaration for ‘Monad A’ }}} could suggest defining it in terms of `Monad`: {{{#!hs <interactive>:3:10: error: • No instance for (Applicative A) arising from the superclasses of an instance declaration • In the instance declaration for ‘Monad A’ • Default implementation given a `Monad` instance: instance Applicative A where pure = return (<*>) = Control.Monad.ap }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11692> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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