January 2016 - ghc-tickets

[GHC] #10592: Allow cycles in class declarations
by GHC 03 Jan '16

03 Jan '16

#10592: Allow cycles in class declarations -------------------------------------+------------------------------------- Reporter: | Owner: MikeIzbicki | Status: new Type: feature | Milestone: request | Version: 7.10.1 Priority: normal | Operating System: Unknown/Multiple Component: Compiler | Type of failure: None/Unknown (Type checker) | Blocked By: Keywords: | Related Tickets: Architecture: | Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- In particular, I would like to have a class hierarchy that looks like: {{{ {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE FlexibleContexts #-} type family Scalar x class Field (Scalar x) => Vector x class Vector x => Field x }}} It is the case that every field is a vector, and the scalar associated with every vector is a field. But we can't currently enforce that. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10592> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4426: Simplify the rules for implicit quantification
by GHC 02 Jan '16

02 Jan '16

#4426: Simplify the rules for implicit quantification -------------------------------------+------------------------------------- Reporter: simonpj | Owner: bgamari Type: feature request | Status: closed Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 6.12.3 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7880 | Differential Rev(s): Phab:D211, Wiki Page: | Phab:D1615 -------------------------------------+------------------------------------- Comment (by Lemming): I defined a type like this one: {{{ newtype T a = Cons (Eq a => b) }}} and GHC-7.10 gave me the warning: {{{ Variable ‘b’ is implicitly quantified due to a context Use explicit forall syntax instead. This will become an error in GHC 7.12. In the type ‘Eq a => b’ In the definition of data constructor ‘Cons’ }}} In this case my mistake was to forget to add the 'b' as type parameter, thus the advice "Use explicit forall syntax instead" was misleading. Could you write instead "Use explicit forall syntax instead or add a type parameter"? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4426#comment:30> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10846: PartialTypeSignatures change implicit CallStack behavior
by GHC 02 Jan '16

02 Jan '16

#10846: PartialTypeSignatures change implicit CallStack behavior -------------------------------------+------------------------------------- Reporter: | Owner: nitromaster101 | Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- I have two functions, f and f2 which are identical expect for the use of PartialTypeSignatures in f2. GHC produces a warning and says that f2's wildcard is filled in by String, which is correct. {{{#!hs {-# LANGUAGE ImplicitParams, PartialTypeSignatures #-} import GHC.Types f :: (?loc :: CallStack) => String f = show $ map (srcLocStartLine . snd) $ getCallStack ?loc f2 :: (?loc :: CallStack) => _ f2 = show $ map (srcLocStartLine . snd) $ getCallStack ?loc f_caller = f f2_caller = f2 }}} {{{ [1 of 1] Compiling Main ( Bug2.hs, interpreted ) Bug2.hs:8:30: warning: Found type wildcard ‘_’ standing for ‘String’ In the type signature for: f2 :: (?loc :: CallStack) => _ Ok, modules loaded: Main. *Main> f_caller "[6,11]" *Main> f2_caller "[9]" }}} f2_caller should have two entries (f2_caller's line and f2's line), just like f_caller. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10846> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11326: bindist built in docker won't install
by GHC 02 Jan '16

02 Jan '16

#11326: bindist built in docker won't install -------------------------------------+------------------------------------- Reporter: alanz | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 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: -------------------------------------+------------------------------------- Building with https://ghc.haskell.org/trac/ghc/wiki/Building/Preparation/Linux#Docker as follows {{{ git checkout e4cc19de4bdbccea589d41717e31d63b088a8990 git submodule update ./configure CPUS=5 ./validate }}} Thereafter {{{ tar xvf ~/mysrc/git.haskell.org/ghc/bindistprep/ghc-7.11.20151229-x86_64 -unknown-linux.tar.bz2 cd ghc-7.11.20151229 ./configure make install }}} Fails with {{{ "utils/ghc-cabal/dist-install/build/tmp/ghc-cabal-bindist" copy libraries /ghc-prim dist-install "strip" '' '/opt/ghc/7.11.20151229' '/opt/ghc/7.11.20151229/lib/ghc-7.11.20151229' '/opt/ghc/7.11.20151229/share/doc/ghc/html/libraries' 'v dyn' ghc-cabal: /home/ghc/libraries/ghc-prim/ghc-prim.cabal: does not exist }}} The path `/home/ghc/libraries/ghc-prim/ghc-prim.cabal` is the absolute path to the file in the docker file system, i.e. it is the location when the tar was constructed. Bisection log {{{ alanz@alanz-laptop:~/mysrc/git.haskell.org/ghc$ git checkout 5bb7fecb09f828ea41e5b5a295ea159fa405dcc5 M libraries/Cabal M libraries/primitive M libraries/unix M utils/haddock Note: checking out '5bb7fecb09f828ea41e5b5a295ea159fa405dcc5'. You are in 'detached HEAD' state. You can look around, make experimental changes and commit them, and you can discard any commits you make in this state without impacting any branches by performing another checkout. If you want to create a new branch to retain commits you create, you may do so (now or later) by using -b with the checkout command again. Example: git checkout -b <new-branch-name> HEAD is now at 5bb7fec... Export some useful GHC API functions. alanz@alanz-laptop:~/mysrc/git.haskell.org/ghc$ git submodule update Submodule path 'libraries/Cabal': checked out '679812d2b679af952a7c9ab45a9a3a3476874a07' Submodule path 'libraries/primitive': checked out '83d3d23d2fa1583ecd1b59464cc889924e1b5fff' Submodule path 'utils/haddock': checked out '80f2f9805b61e8cea291bae8ce22db626dc11f21' alanz@alanz-laptop:~/mysrc/git.haskell.org/ghc$ git bisect good Bisecting: 11 revisions left to test after this (roughly 4 steps) [c06b46d0313cafe05f8250a660b4481d7c1d298f] Fix #11305. alanz@alanz-laptop:~/mysrc/git.haskell.org/ghc$ git bisect bad Bisecting: 5 revisions left to test after this (roughly 3 steps) [fcc76493c8b35001fc1b22738cc64ff9506e278a] Introduce negative patterns for literals (addresses #11303) alanz@alanz-laptop:~/mysrc/git.haskell.org/ghc$ alanz@alanz-laptop:~/mysrc/git.haskell.org/ghc$ alanz@alanz-laptop:~/mysrc/git.haskell.org/ghc$ alanz@alanz-laptop:~/mysrc/git.haskell.org/ghc$ git bisect good Bisecting: 2 revisions left to test after this (roughly 2 steps) [e4cc19de4bdbccea589d41717e31d63b088a8990] Update Cabal submodule to latest snapshot alanz@alanz-laptop:~/mysrc/git.haskell.org/ghc$ git bisect bad Bisecting: 0 revisions left to test after this (roughly 1 step) [adcbc98f50cd6bb01dfcf4c98ad5fe414f7cc40c] Add regression test for #11303 alanz@alanz-laptop:~/mysrc/git.haskell.org/ghc$ git bisect good e4cc19de4bdbccea589d41717e31d63b088a8990 is the first bad commit commit e4cc19de4bdbccea589d41717e31d63b088a8990 Author: Herbert Valerio Riedel <hvr(a)gnu.org> Date: Tue Dec 29 22:19:54 2015 +0100 Update Cabal submodule to latest snapshot :040000 040000 9ba8cf17f85a186265761f3f1e4a11c809d0a54f 7cec7703b483a73f07d2414b364e0f3923970b1f M libraries }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11326> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11321: API Annotations: AnnTilde missing
by GHC 02 Jan '16

02 Jan '16

#11321: API Annotations: AnnTilde missing -------------------------------------+------------------------------------- Reporter: alanz | Owner: alanz Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.10.3 Keywords: | Operating System: Unknown/Multiple ApiAnnotations | Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- In T10689a.hs, the fragment {{{#!hs data instance Sing (z :: [a]) = z ~ '[] => SNil | forall (m :: a) (n :: [a]). z ~ (:) m n => SCons (Sing m) (Sing n) }}} ends up with the `AnnTilde` annotations for the two tildes not attached to the final AST. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11321> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11332: APIAnnotations: AnnDotDot missing for Pattern Synonym export
by GHC 02 Jan '16

02 Jan '16

#11332: APIAnnotations: AnnDotDot missing for Pattern Synonym export -------------------------------------+------------------------------------- Reporter: alanz | Owner: alanz Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 8.1 (Parser) | Keywords: | Operating System: Unknown/Multiple ApiAnnotations | Architecture: | Type of failure: Other Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- For the following code fragment {{{#!hs {-# LANGUAGE PatternSynonyms #-} module ExportSyntax ( A(.., NoA), Q(F,..), G(T,..,U)) where }}} The second and third `..` are missing `AnnDotdot` annotations. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11332> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9590: AMP breaks `haskell2010` package
by GHC 02 Jan '16

02 Jan '16

#9590: AMP breaks `haskell2010` package -------------------------------------+------------------------------------- Reporter: hvr | Owner: Type: bug | Status: new Priority: high | Milestone: 7.10.1 Component: | Version: 7.9 libraries/haskell2010 | Operating System: Keywords: AMP | Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: GHC Difficulty: Unknown | rejects valid program Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- (and probably also `haskell98`) I hate to be the one pointing this out, but the AMP has one ugly side- effect. Consider the following session: ``` $ inplace/bin/ghc-stage2 --interactive -XHaskell2010 -hide-all-packages -package haskell2010 GHCi, version 7.9.20140914: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim-0.3.1.0 ... linking ... done. Loading package integer-gmp-0.5.1.0 ... linking ... done. Loading package base-4.8.0.0 ... linking ... done. Loading package array-0.5.0.1 ... linking ... done. Loading package haskell2010-1.1.2.1 ... linking ... done. λ:2> data Identity a = Identity a data Identity a = Identity a λ:3> instance Monad Identity <interactive>:3:10: No instance for (base-4.8.0.0:GHC.Base.Applicative Identity) arising from the superclasses of an instance declaration In the instance declaration for ‘Monad Identity’ λ:4> :info Monad class base-4.8.0.0:GHC.Base.Applicative m => Monad (m :: * -> *) where (>>=) :: m a -> (a -> m b) -> m b (>>) :: m a -> m b -> m b return :: a -> m a fail :: String -> m a -- Defined in ‘base-4.8.0.0:GHC.Base’ instance Monad (Either e) -- Defined in ‘base-4.8.0.0:Data.Either’ instance Monad Maybe -- Defined in ‘base-4.8.0.0:Data.Maybe’ instance Monad [] -- Defined in ‘base-4.8.0.0:GHC.Base’ instance Monad IO -- Defined in ‘base-4.8.0.0:GHC.Base’ instance Monad ((->) r) -- Defined in ‘base-4.8.0.0:GHC.Base’ λ:5> ``` -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9590> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #2258: ghc --cleanup
by GHC 02 Jan '16

02 Jan '16

#2258: ghc --cleanup -------------------------------------+------------------------------------- Reporter: claus | Owner: Type: feature request | Status: new Priority: lowest | Milestone: 8.0.1 Component: Compiler | Version: 6.8.2 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #4114 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bheklilr): Replying to [comment:24 thomie]: > Unassigning, because of lack of progress. > > Maybe somebody else wants to give this a shot? @bheklilr? Sure, I'll give it a shot. It'll be a few days until I can look at it, the holidays have been keeping me busy (hence my delayed response), but I think I could take a stab at it sometime this month. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/2258#comment:25> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11135: Migrate more of Data.Functor.* from transformers to base.
by GHC 02 Jan '16

02 Jan '16

#11135: Migrate more of Data.Functor.* from transformers to base. -------------------------------------+------------------------------------- Reporter: hvr | Owner: Type: task | Status: new Priority: highest | Milestone: 8.0.1 Component: | Version: 7.10.2 libraries/base | 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: -------------------------------------+------------------------------------- This was proposed in https://mail.haskell.org/pipermail/libraries/2015-July/026014.html Edward says the following modules are up for migration: - `Data.Functor.Classes` - `Data.Functor.Product` - `Data.Functor.Sum` - `Data.Functor.Compose` related/optionally/undecided: - `Data.Functor.Reverse` - `Control.Applicative.Backwards` not moved because redundant (c.f. `Const`): - `Data.Functor.Constant` -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11135> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11296: T8726 fails on arm
by GHC 02 Jan '16

02 Jan '16

#11296: T8726 fails on arm -------------------------------------+------------------------------------- Reporter: bgamari | Owner: bgamari Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.10.3 Keywords: | Operating System: Linux Architecture: arm | Type of failure: Incorrect result | at runtime Test Case: T8726 | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{ cd ./numeric/should_run && ./T8726 </dev/null > T8726.run.stdout 2> T8726.run.stderr Wrong exit code (expected 0 , actual 1 ) Stdout: Stderr: T8726: user error (divMod0 -2 79228162514264337593543950336) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11296> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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