[GHC] #10242: Multiple constraint wildcards allowed with PartialTypeSignatures
#10242: Multiple constraint wildcards allowed with PartialTypeSignatures -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Keywords: | Operating System: Unknown/Multiple PartialTypeSignatures | Type of failure: GHC accepts Architecture: | invalid program Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- The [https://ghc.haskell.org/trac/ghc/wiki/PartialTypeSignatures wiki] states that
As a single extra-constraints wildcard is enough to infer any number of constraints, only one is allowed in a type signature and it should come last in the list of constraints.
However the following program compiles with GHC 7.10.1 {{{#!hs {-# LANGUAGE PartialTypeSignatures #-} f :: (Eq a, _, _) => a -> a -> Bool f x y = x == y }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10242> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#10242: Multiple constraint wildcards allowed with PartialTypeSignatures -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | PartialTypeSignatures Type of failure: GHC accepts | Architecture: invalid program | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Changes (by simonpj): * cc: dominique.devriese@…, Thomas, Winant, <thomas.winant@…> (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10242#comment:1> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#10242: Multiple constraint wildcards allowed with PartialTypeSignatures -------------------------------------+------------------------------------- Reporter: mpickering | Owner: thomasw Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | PartialTypeSignatures Type of failure: GHC accepts | Architecture: invalid program | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Changes (by thomasw): * owner: => thomasw -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10242#comment:2> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#10242: Multiple constraint wildcards allowed with PartialTypeSignatures -------------------------------------+------------------------------------- Reporter: mpickering | Owner: thomasw Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | PartialTypeSignatures Type of failure: GHC accepts | Architecture: invalid program | Unknown/Multiple Blocked By: | Test Case: Related Tickets: #10098 | Blocking: | Differential Revisions: Phab:D613 -------------------------------------+------------------------------------- Changes (by thomasw): * differential: => Phab:D613 * related: => #10098 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10242#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#10242: Multiple constraint wildcards allowed with PartialTypeSignatures -------------------------------------+------------------------------------- Reporter: mpickering | Owner: thomasw Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | PartialTypeSignatures Type of failure: GHC accepts | Architecture: invalid program | Unknown/Multiple Blocked By: | Test Case: Related Tickets: #10098 | Blocking: | Differential Revisions: Phab:D613 -------------------------------------+------------------------------------- Comment (by thomasw): This is fixed by Phab:D613, which still needs to be merged. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10242#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#10242: Multiple constraint wildcards allowed with PartialTypeSignatures -------------------------------------+------------------------------------- Reporter: mpickering | Owner: thomasw Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | PartialTypeSignatures Type of failure: GHC accepts | Architecture: invalid program | Unknown/Multiple Blocked By: | Test Case: Related Tickets: #10098 | Blocking: | Differential Revisions: Phab:D613 -------------------------------------+------------------------------------- Comment (by simonpj): Good. Let's land Phab:D613. I doubt it's worth putting it into 7.10.2 Austin can you do that? Simon -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10242#comment:5> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#10242: Multiple constraint wildcards allowed with PartialTypeSignatures -------------------------------------+------------------------------------- Reporter: mpickering | Owner: thomasw Type: bug | Status: closed Priority: normal | Milestone: 7.10.3 Component: Compiler | Version: 7.10.1 Resolution: fixed | Keywords: | PartialTypeSignatures Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: GHC accepts | Test Case: partial- invalid program | sigs/should_fail/ExtraConstraintsWildcardTwice Blocked By: | Blocking: Related Tickets: #10098 | Differential Rev(s): Phab:D613 Wiki Page: | -------------------------------------+------------------------------------- Changes (by thomie): * status: new => closed * testcase: => partial-sigs/should_fail/ExtraConstraintsWildcardTwice * resolution: => fixed * milestone: => 7.10.3 Comment: Already fixed. Milestone should really be 7.10.2. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10242#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#10242: Multiple constraint wildcards allowed with PartialTypeSignatures -------------------------------------+------------------------------------- Reporter: mpickering | Owner: thomasw Type: bug | Status: closed Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.10.1 Resolution: fixed | Keywords: | PartialTypeSignatures Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: GHC accepts | Test Case: partial- invalid program | sigs/should_fail/ExtraConstraintsWildcardTwice Blocked By: | Blocking: Related Tickets: #10098 | Differential Rev(s): Phab:D613 Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * milestone: 7.10.3 => 8.0.1 Comment: This won't be going in to 7.10.3. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10242#comment:7> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
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