- ghc-tickets - Haskell.org

Re: [GHC] #7863: Verbosity level for quieter Template Haskell
by GHC 20 Sep '14

20 Sep '14

#7863: Verbosity level for quieter Template Haskell -------------------------------------+------------------------------------- Reporter: dolio | Owner: Type: feature | Status: new request | Milestone: 7.10.1 Priority: low | Version: 7.6.3 Component: Template | Keywords: linker Haskell | Architecture: Unknown/Multiple Resolution: | Difficulty: Unknown Operating System: | Blocked By: Unknown/Multiple | Related Tickets: #5647 Type of failure: | None/Unknown | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Changes (by hvr): * related: => #5647 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7863#comment:5> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

[GHC] #9610: Missing fixity declaration for `Data.Foldable.{elem, notElem}`
by GHC 20 Sep '14

20 Sep '14

#9610: Missing fixity declaration for `Data.Foldable.{elem,notElem}` -------------------------------------+------------------------------------- Reporter: hvr | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.10.1 Component: libraries/base | Version: 7.8.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: #9586 | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- `Data.Foldable.{elem,notElem}` is lacking the fixity declaration {{{#!hs infix 4 `elem`, `notElem` }}} to match their monomorphic `Data.List` counterparts' fixity. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9610> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #9580: Possible excessive leniency in interaction between coerce and data families?
by GHC 19 Sep '14

19 Sep '14

#9580: Possible excessive leniency in interaction between coerce and data families? -------------------------------------+------------------------------------- Reporter: dmcclean | Owner: Type: bug | Status: new Priority: low | Milestone: Component: Compiler (Type | Version: 7.8.3 checker) | Operating System: Keywords: | Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: Difficulty: Unknown | None/Unknown Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Per goldfire's request at #8177, I am promoting this issue into it's own ticket. I am entirely not confident that it represents a bug; I raise the issue because, while it happens to do exactly what I want, I cannot understand *why* it does what I want, and it seems like it might possibly also do related undesirable things. I have the following situation, which I have distilled from a real use case, retaining its identifiers but eliding a whole bunch of irrelevant detail. The real thing is on GitHub if it helps anyone to see why I want to do this, but it's really a side issue AFAICT. It's split into two modules, because goldfire had suggested that it might have arisen because the newtype constructor `Quantity'` was in scope at the site of the `coerce`, this test shows that it arises even when `Quantity'` is not in scope. {{{ {-# LANGUAGE DataKinds #-} {-# LANGUAGE KindSignatures #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE FlexibleInstances #-} module Test ( Quantity, Unit, Dimension(..), Variant(..), Mass, KnownVariant(Dimensional) ) where data Variant = DQuantity | DUnit data Dimension = DMass | DLength | DTime -- ... this isn't the real way, it's simplified data UnitName = UnitName String class KnownVariant (var :: Variant) where data Dimensional var :: Dimension -> * -> * instance KnownVariant DQuantity where newtype Dimensional DQuantity d v = Quantity' v instance KnownVariant DUnit where data Dimensional DUnit d v = Unit' UnitName v instance (Show v) => Show (Dimensional DQuantity d v) where show (Quantity' x) = "As A Quantity " ++ show x type Quantity = Dimensional DQuantity type Unit = Dimensional DUnit type Mass v = Quantity DMass v }}} And the main module: {{{ module Main where import Test import Data.Coerce main = do let x = 3.7 :: Double putStrLn . show $ x let y = (coerce x) :: Mass Double putStrLn . show $ y let z = (coerce y) :: Double putStrLn . show $ z }}} My question is in two parts: 1) Why are these coercions allowed if the role signature of `Dimensional` is, as GHCi's :i tells me, nominal nominal nominal? 2) Is this the intended behavior? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9580> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 10

Re: [GHC] #4426: Simplify the rules for implicit quantification
by GHC 19 Sep '14

19 Sep '14

#4426: Simplify the rules for implicit quantification -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: feature | Status: new request | Milestone: 7.10.1 Priority: highest | Version: 6.12.3 Component: Compiler | Keywords: Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: | Related Tickets: #7880 None/Unknown | Test Case: | Blocking: | Differential Revisions: Phab:D211 | -------------------------------------+------------------------------------- Comment (by goldfire): I'm very late to this conversation, so please ignore me if this is silly. Why not just jump the gun and make this an error right now? Has anyone tried to see how many packages on Hackage this would break? Spreading the effects of this change over 3 releases (warning in 7.10, error in 7.12 while deprecating the warning flag, remove warning flag in 7.14) seems like a lot of overhead when the amount of affected code is (in my uneducated guess) very small. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4426#comment:18> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

Re: [GHC] #5395: Context reduction stack overflow without undecidable instances
by GHC 19 Sep '14

19 Sep '14

#5395: Context reduction stack overflow without undecidable instances -------------------------------------+------------------------------------- Reporter: guest | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.0.4 Resolution: fixed | Keywords: type family, Operating System: | termination Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: GHC | Difficulty: Unknown rejects valid program | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Changes (by simonpj): * status: new => closed * resolution: => fixed Comment: Done! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5395#comment:11> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

[GHC] #9528: typo in man-page/docs
by GHC 19 Sep '14

19 Sep '14

#9528: typo in man-page/docs -------------------------------------+------------------------------------- Reporter: lspitzner | Owner: Type: bug | Status: new Priority: lowest | Milestone: Component: Documentation | Version: 7.8.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Easy (less than 1 | Type of failure: hour) | None/Unknown Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- "rrestriction" in ghc/docs/users_guide/flags.xml -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9528> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 4

Re: [GHC] #5395: Context reduction stack overflow without undecidable instances
by GHC 19 Sep '14

19 Sep '14

#5395: Context reduction stack overflow without undecidable instances -------------------------------------+------------------------------------- Reporter: guest | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.0.4 Resolution: | Keywords: type family, Operating System: | termination Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: GHC | Difficulty: Unknown rejects valid program | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"c96c64fae0152bc53f48634d0ddd310ef4bc0105/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="c96c64fae0152bc53f48634d0ddd310ef4bc0105" Increase -fcontext-stack=N default to 100 This addresses Trac #5395 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5395#comment:10> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

Re: [GHC] #4426: Simplify the rules for implicit quantification
by GHC 19 Sep '14

19 Sep '14

#4426: Simplify the rules for implicit quantification -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: feature | Status: new request | Milestone: 7.10.1 Priority: highest | Version: 6.12.3 Component: Compiler | Keywords: Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: | Related Tickets: #7880 None/Unknown | Test Case: | Blocking: | Differential Revisions: Phab:D211 | -------------------------------------+------------------------------------- Changes (by simonpj): * priority: low => highest * status: closed => new * resolution: fixed => Comment: No, now, let's not close this. There's a pending change for 7.12, namely * making the warnings into an error. * getting rid of the `Qualified` constructor in `HsExplicitFlag` (we can use `Explicit` instead) * remove or deprecate `fwarn-context-quantification` (I suppose it should be deprecated until 7.14, sigh.) 7.12 isn't a milestone yet (Austin can you fix that?), so I'll milestone it for 7.10 so it doesn't get lost. I'll give it "highest" priority not because it's terribly vital but because it's easy and it'd be untidy to let it linger. Simon -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4426#comment:17> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

Re: [GHC] #4426: Simplify the rules for implicit quantification
by GHC 19 Sep '14

19 Sep '14

#4426: Simplify the rules for implicit quantification -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: feature | Status: closed request | Milestone: 7.10.1 Priority: low | Version: 6.12.3 Component: Compiler | Keywords: Resolution: fixed | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: | Related Tickets: #7880 None/Unknown | Test Case: | Blocking: | Differential Revisions: Phab:D211 | -------------------------------------+------------------------------------- Changes (by ezyang): * status: patch => closed * resolution: => fixed -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4426#comment:16> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

Re: [GHC] #4426: Simplify the rules for implicit quantification
by GHC 19 Sep '14

19 Sep '14

#4426: Simplify the rules for implicit quantification -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: feature | Status: patch request | Milestone: 7.10.1 Priority: low | Version: 6.12.3 Component: Compiler | Keywords: Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: | Related Tickets: #7880 None/Unknown | Test Case: | Blocking: | Differential Revisions: Phab:D211 | -------------------------------------+------------------------------------- Comment (by Edward Z. Yang <ezyang@…>): In [changeset:"275dcafbfb6b371dd5d8943fa4df9c23e68f6165/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="275dcafbfb6b371dd5d8943fa4df9c23e68f6165" Add -fwarn-context-quantification (#4426) Summary: This warning (enabled by default) reports places where a context implicitly binds a type variable, for example type T a = {-forall m.-} Monad m => a -> m a Also update Haddock submodule. Test Plan: validate Reviewers: hvr, goldfire, simonpj, austin Reviewed By: austin Subscribers: simonmar, ezyang, carter Differential Revision: https://phabricator.haskell.org/D211 GHC Trac Issues: #4426 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4426#comment:15> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0