[GHC] #12399: DeriveFunctor fail
#12399: DeriveFunctor fail -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 (Type checker) | 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: -------------------------------------+------------------------------------- {{{#!haskell {-# LANGUAGE DeriveFunctor, MagicHash, UnboxedTuples #-} module Lib where import GHC.Exts newtype RmLoopsM a = RmLoopsM { runRmLoops :: Int# -> (# Int#, a #) } }}} Functor instance for this can be derived like this: {{{#!haskell instance Functor RmLoopsM where fmap f (RmLoopsM m) = RmLoopsM $ \i -> case m i of (# i', r #) -> (# i', f r #) }}} `DeriveFunctor` instead generates something like this: {{{#!haskell instance Functor RmLoopsM where fmap f_a2Oh (Lib.RmLoopsM a1_a2Oi) = RmLoopsM ((\ b6_a2Oj b7_a2Ok -> (\ b5_a2Ol -> case b5_a2Ol of { ((#,#) a1_a2Om a2_a2On a3_a2Oo a4_a2Op) -> (#,#) ((\ b2_a2Oq -> b2_a2Oq) a1_a2Om) ((\ b3_a2Or -> b3_a2Or) a2_a2On) ((\ b4_a2Os -> b4_a2Os) a3_a2Oo) (f_a2Oh a4_a2Op) }) (b6_a2Oj ((\ b1_a2Ot -> b1_a2Ot) b7_a2Ok))) a1_a2Oi) }}} which fails with {{{ Main.hs:17:25: error: • The constructor ‘(#,#)’ should have 2 arguments, but has been given 4 • In the pattern: (#,#) a1_a2Om a2_a2On a3_a2Oo a4_a2Op In a case alternative: ((#,#) a1_a2Om a2_a2On a3_a2Oo a4_a2Op) -> (#,#) ((\ b2_a2Oq -> b2_a2Oq) a1_a2Om) ((\ b3_a2Or -> b3_a2Or) a2_a2On) ((\ b4_a2Os -> b4_a2Os) a3_a2Oo) (f_a2Oh a4_a2Op) In the expression: case b5_a2Ol of { ((#,#) a1_a2Om a2_a2On a3_a2Oo a4_a2Op) -> (#,#) ((\ b2_a2Oq -> b2_a2Oq) a1_a2Om) ((\ b3_a2Or -> b3_a2Or) a2_a2On) ((\ b4_a2Os -> b4_a2Os) a3_a2Oo) (f_a2Oh a4_a2Op) } }}} I think it's supposed to ignore RuntimeRep args during the fold (`TcGenDeriv.functorLikeTraverse`). Tried with: HEAD, 8.0.1. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12399 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12399: DeriveFunctor fail -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler (Type | Version: 8.1 checker) | Resolution: | 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 bgamari): * cc: RyanGlScott (added) * milestone: => 8.2.1 Comment: Adding RyanGlScott who has done a fair bit of work in this area. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12399#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12399: DeriveFunctor fail -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: bug | Status: patch Priority: normal | Milestone: 8.2.1 Component: Compiler (Type | Version: 8.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2404 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => patch * differential: => Phab:D2404 Comment: Nice catch! I had no idea that `RuntimeRep`-kinded type parameters were also represented as actual arguments to a constructor... in any case, your intuition that we need to drop the `RuntimeRep` args was spot on. (Hopefully, this would also fix derived `Functor` instances for datatypes that contain unboxed sums, but I'm not 100% sure on that.) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12399#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12399: DeriveFunctor fail
-------------------------------------+-------------------------------------
Reporter: osa1 | Owner:
Type: bug | Status: patch
Priority: normal | Milestone: 8.2.1
Component: Compiler (Type | Version: 8.1
checker) |
Resolution: | Keywords:
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s): Phab:D2404
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by Ryan Scott
#12399: DeriveFunctor fail -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: bug | Status: closed Priority: normal | Milestone: 8.0.2 Component: Compiler (Type | Version: 8.1 checker) | Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2404 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: patch => closed * resolution: => fixed * milestone: 8.2.1 => 8.0.2 Comment: I think this deserves to go into 8.0.2, if possible. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12399#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12399: DeriveFunctor fail -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: bug | Status: merge Priority: normal | Milestone: 8.0.2 Component: Compiler (Type | Version: 8.1 checker) | Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2404 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: closed => merge -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12399#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12399: DeriveFunctor fail -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: bug | Status: merge Priority: normal | Milestone: 8.0.2 Component: Compiler (Type | Version: 8.1 checker) | Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | deriving/should_compile/T12399 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2404 Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * testcase: => deriving/should_compile/T12399 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12399#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12399: DeriveFunctor fail
-------------------------------------+-------------------------------------
Reporter: osa1 | Owner:
Type: bug | Status: merge
Priority: normal | Milestone: 8.0.2
Component: Compiler (Type | Version: 8.1
checker) |
Resolution: fixed | Keywords:
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
| deriving/should_compile/T12399
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s): Phab:D2404
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by Ben Gamari
#12399: DeriveFunctor fail -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: bug | Status: closed Priority: normal | Milestone: 8.0.2 Component: Compiler (Type | Version: 8.1 checker) | Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | deriving/should_compile/T12399 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2404 Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: merge => closed -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12399#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12399: DeriveFunctor fail -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: bug | Status: closed Priority: normal | Milestone: 8.0.2 Component: Compiler (Type | Version: 8.0.1 checker) | Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | deriving/should_compile/T12399 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2404 Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * version: 8.1 => 8.0.1 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12399#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12399: DeriveFunctor fail -------------------------------------+------------------------------------- Reporter: osa1 | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 8.0.2 Component: Compiler (Type | Version: 8.0.1 checker) | Resolution: fixed | Keywords: deriving Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | deriving/should_compile/T12399 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2404 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * keywords: => deriving -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12399#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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