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[GHC] #10119: Class methods must always mention the class variable
by GHC 04 Mar '15

04 Mar '15

#10119: Class methods must always mention the class variable -------------------------------------+------------------------------------- Reporter: thomie | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.10.1-rc2 (Type checker) | Operating System: Unknown/Multiple Keywords: | Type of failure: None/Unknown Architecture: | Blocked By: Unknown/Multiple | Related Tickets: #7854, #10118 Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- As mentioned in comment:9:ticket:7854, GHC wrongfully accepts the following program. It should reject it, because `op` doesn't mention any type variables of `Foo` (the method context doesn't count). {{{#!hs module ShouldFail where class Foo a where op :: Eq a => Int }}} I'm working on it. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10119> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7854: Constrained method type accepted in Haskell 98 mode
by GHC 04 Mar '15

04 Mar '15

#7854: Constrained method type accepted in Haskell 98 mode -------------------------------------+------------------------------------- Reporter: refold | Owner: thomie Type: bug | Status: closed Priority: normal | Milestone: 7.12.1 Component: Compiler (Type | Version: 7.6.3 checker) | Keywords: newcomer Resolution: fixed | Architecture: Operating System: Unknown/Multiple | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | module/mod39 Related Tickets: #10118, #10119 | Blocking: | Differential Revisions: Phab:D688 -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"3aa2519ec29156f57a862a033bc7a902b742a2e0/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="3aa2519ec29156f57a862a033bc7a902b742a2e0" Check for equality before deferring This one was a bit of a surprise. In fixing Trac #7854, I moved the checkAmbiguity tests to checkValidType. That meant it happened even for monotypes, and that turned out to be very expensive in T9872a, for reasons described in this (new) Note in TcUnify: Note [Check for equality before deferring] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Particularly in ambiguity checks we can get equalities like (ty ~ ty). If ty involves a type function we may defer, which isn't very sensible. An egregious example of this was in test T9872a, which has a type signature Proxy :: Proxy (Solutions Cubes) Doing the ambiguity check on this signature generates the equality Solutions Cubes ~ Solutions Cubes and currently the constraint solver normalises both sides at vast cost. This little short-cut in 'defer' helps quite a bit. I fixed the problem with a quick equality test, but it feels like an ad- hoc solution; I think we might want to do something in the constraint solver too. (The problem was there all along, just more hidden.) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7854#comment:14> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7854: Constrained method type accepted in Haskell 98 mode
by GHC 04 Mar '15

04 Mar '15

#7854: Constrained method type accepted in Haskell 98 mode -------------------------------------+------------------------------------- Reporter: refold | Owner: thomie Type: bug | Status: closed Priority: normal | Milestone: 7.12.1 Component: Compiler (Type | Version: 7.6.3 checker) | Keywords: newcomer Resolution: fixed | Architecture: Operating System: Unknown/Multiple | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | module/mod39 Related Tickets: #10118, #10119 | Blocking: | Differential Revisions: Phab:D688 -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"9dc0d63cd7231392320e4afcfe78102801126d34/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="9dc0d63cd7231392320e4afcfe78102801126d34" Three other test updates following the fix to Trac #7854 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7854#comment:15> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7854: Constrained method type accepted in Haskell 98 mode
by GHC 04 Mar '15

04 Mar '15

#7854: Constrained method type accepted in Haskell 98 mode -------------------------------------+------------------------------------- Reporter: refold | Owner: thomie Type: bug | Status: closed Priority: normal | Milestone: 7.12.1 Component: Compiler (Type | Version: 7.6.3 checker) | Keywords: newcomer Resolution: fixed | Architecture: Operating System: Unknown/Multiple | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | module/mod39 Related Tickets: #10118, #10119 | Blocking: | Differential Revisions: Phab:D688 -------------------------------------+------------------------------------- Changes (by simonpj): * status: patch => closed * testcase: typechecker/should_fail/T7854 => module/mod39 * resolution: => fixed Comment: OK done. I suggest we don't push this to 7.10 in case it breaks things. Simon -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7854#comment:13> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10102: GHC inlines past lambda in do-notation
by GHC 04 Mar '15

04 Mar '15

#10102: GHC inlines past lambda in do-notation -------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Hi, a friend of mine discovered this weird behaviour: The program, when run on the attached file, takes quite some time. {{{ import System.IO import Control.Monad import qualified Data.Map as M main :: IO () main = do n <- read `fmap` getLine q <- read `fmap` getLine mts <- replicateM n $ do [a,b] <- words `fmap` getLine return (a,b) let mtdb2 = M.fromList mts --M.null mtdb2 `seq` return () replicateM_ q $ do a <- getLine print $ M.lookup a mtdb2 return () }}} But if I uncomment the use of `mtdb2` outside the replicate, it runs fast. My conclusion is that GHC inlines `mtdb2` into the body of the loop, repeating the construction of the map over and over. If `forM [1..q] $ \_ -> do` is used instead, this does not happen – probably because GHC does _not_ inline past that lambda. (I didn’t attempt to understand the core yet) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10102> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7854: Constrained method type accepted in Haskell 98 mode
by GHC 04 Mar '15

04 Mar '15

#7854: Constrained method type accepted in Haskell 98 mode -------------------------------------+------------------------------------- Reporter: refold | Owner: thomie Type: bug | Status: patch Priority: normal | Milestone: 7.12.1 Component: Compiler (Type | Version: 7.6.3 checker) | Keywords: newcomer Resolution: | Architecture: Operating System: Unknown/Multiple | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | typechecker/should_fail/T7854 Related Tickets: #10118, #10119 | Blocking: | Differential Revisions: Phab:D688 -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"f66e0e695b0377c469fbe877d4850fc0ebca2010/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="f66e0e695b0377c469fbe877d4850fc0ebca2010" A raft of small changes associated with -XConstrainedClassMethods See Trac #7854. Specifically: * Major clean up and simplification of check_op in checkValidClass; specifically - use checkValidType on the entire method-selector type to detect ambiguity - put a specific test for -XConstrainedClassMethods * Make -XConstrainedClassMethods be implied by -XMultiParamTypeClasses (a bit ad-hoc but see #7854), and document in the user manual. * Do the checkAmbiguity test just once in TcValidity.checkValidType, rather than repeatedly at every level. See Note [When to call checkAmbiguity] * Add -XAllowAmbiguousTypes in GHC.IP, since 'ip' really is ambiguous. (It's a rather magic function.) * Improve location info for check_op in checkValidClass * Update quite a few tests, which had genuinely-ambiguous class method signatures. Some I fixed by making them unambiguous; some by adding -XAllowAmbiguousTypes }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7854#comment:12> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #2991: .tix file generation broken with -fhpc and --make flags with lhs modules
by GHC 04 Mar '15

04 Mar '15

#2991: .tix file generation broken with -fhpc and --make flags with lhs modules -------------------------------------+------------------------------------- Reporter: ppavel | Owner: andy@… Type: bug | Status: patch Priority: lowest | Milestone: 7.12.1 Component: Code Coverage | Version: 6.10.1 Resolution: | Keywords: hpc make Operating System: Unknown/Multiple | lhs Type of failure: None/Unknown | Architecture: Blocked By: | Unknown/Multiple Related Tickets: | Test Case: hpc/T2991 | Blocking: | Differential Revisions: Phab:D701 -------------------------------------+------------------------------------- Changes (by thomie): * status: new => patch * testcase: => hpc/T2991 * differential: => Phab:D701 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/2991#comment:16> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7854: Constrained method type accepted in Haskell 98 mode
by GHC 04 Mar '15

04 Mar '15

#7854: Constrained method type accepted in Haskell 98 mode -------------------------------------+------------------------------------- Reporter: refold | Owner: thomie Type: bug | Status: patch Priority: normal | Milestone: 7.12.1 Component: Compiler (Type | Version: 7.6.3 checker) | Keywords: newcomer Resolution: | Architecture: Operating System: Unknown/Multiple | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | typechecker/should_fail/T7854 Related Tickets: #10118, #10119 | Blocking: | Differential Revisions: Phab:D688 -------------------------------------+------------------------------------- Comment (by simonpj): Thomie, thanks for working on this. Inspired by your patches I can see a simpler way to achieve the same goal, so I'll do that. Specifically I plan to do this: * Fix the original bug simply by always doing a `checkValidType` on the entire selector-id type. That includes an ambiguity check which is precisely what we need. * Implement the check when `ConstrainedClassMethods` is ''off'' as a special check that does nothing else. * As comment:4 acknowledges, GHC has not been making the claimed check for ages. Rather than making `ConstrainedClassMethods` on by default (as you propose), I plan to make it implied by `MultiParamTypeClasses`, which means that we are out of Haskell-98 land anyway. This means that some programs may break, but (a) the error message suggests adding `ConstrainedClassMethods` (b) the fix is easy. If necessary (e.g. on a Stackage run) we can make it on-by-default in 7.10 to ease transition. Commit coming. Thanks for unblocking this. Simon -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7854#comment:11> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10136: Female athletes RageDNA
by GHC 04 Mar '15

04 Mar '15

#10136: Female athletes RageDNA -------------------------------------+------------------------------------- Reporter: | Owner: RTromeen1955 | Status: new Type: bug | Milestone: Priority: normal | Version: 7.8.4 Component: Compiler | Operating System: Unknown/Multiple Keywords: RageDNA | Type of failure: None/Unknown Architecture: | Blocked By: Unknown/Multiple | Related Tickets: RageDNA Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Female athletes go prepared and take appropriate sports clothing, as the workshop will be theoretical and practical. [http://supertestoboostsfacts.com/ragedna/ RageDNA] Also for male athletes come prepared athletically, since the seminar includes the art of posing. Do not miss this opportunity offered by the highest authority of our sport IFBB in Honduras to learn more about the world of bodybuilding and fitness, can also share and meet with leading and experienced athletes in our sport.. http://supertestoboostsfacts.com/ragedna/ -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10136> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10135: This Saturday February RageDNA
by GHC 04 Mar '15

04 Mar '15

#10135: This Saturday February RageDNA -------------------------------------+------------------------------------- Reporter: | Owner: RTromeen1955 | Status: new Type: bug | Milestone: Priority: normal | Version: 7.8.4 Component: Compiler | Operating System: Unknown/Multiple Keywords: RageDNA | Type of failure: None/Unknown Architecture: | Blocked By: Unknown/Multiple | Related Tickets: RageDNA Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- This Saturday February 28th (for the Central region, South and East) in CONDEPAH facilities in the Olympic Village from 9:00 am. Similarly the same [http://supertestoboostsfacts.com/ragedna/ RageDNA] activity will be held on Saturday March 7 (North Zone and West) at the premises of VIP Nautilus Gym San Pedro Sula from 9:00 am This activity has no cost, so they are invited to be trained and learn about our sport and the basis for this 2015... http://supertestoboostsfacts.com/ragedna/ -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10135> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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