[GHC] #11964: Without TypeInType, inconsistently accepts Data.Kind.Type but not type synonym
#11964: Without TypeInType, inconsistently accepts Data.Kind.Type but not type synonym -------------------------------------+------------------------------------- Reporter: ezyang | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc2 (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: -------------------------------------+------------------------------------- For convenience, I'll use GHCi to demonstrate flag behavior. First, we define a file: ``` {-# LANGUAGE TypeInType #-} import Data.Kind type Star = Type newtype T k (t :: k) = T () ``` Next, we load it up in GHCi, WITHOUT `-XTypeInType`. Now we observe strange behavior: ``` ezyang@sabre:~$ ghc-8.0 --interactive C.hs GHCi, version 8.0.0.20160204: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( C.hs, interpreted ) Ok, modules loaded: Main. *Main> :k T Type Int T Type Int :: * *Main> :k T Star Int <interactive>:1:3: error: • Data constructor ‘Star’ cannot be used here (Perhaps you intended to use DataKinds) • In the first argument of ‘T’, namely ‘Star’ In the type ‘T Star Int’ ``` Of course, if we pass `-TypeInType` to GHCi that fixes the problem (BTW, `DataKinds` does NOT solve the problem.) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11964 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#11964: Without TypeInType, inconsistently accepts Data.Kind.Type but not type synonym -------------------------------------+------------------------------------- Reporter: ezyang | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.0.1-rc2 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: | -------------------------------------+------------------------------------- Description changed by ezyang: @@ -4,1 +4,1 @@ - ``` + {{{ @@ -9,1 +9,1 @@ - ``` + }}} @@ -14,1 +14,1 @@ - ``` + {{{ @@ -28,1 +28,1 @@ - ``` + }}} New description: For convenience, I'll use GHCi to demonstrate flag behavior. First, we define a file: {{{ {-# LANGUAGE TypeInType #-} import Data.Kind type Star = Type newtype T k (t :: k) = T () }}} Next, we load it up in GHCi, WITHOUT `-XTypeInType`. Now we observe strange behavior: {{{ ezyang@sabre:~$ ghc-8.0 --interactive C.hs GHCi, version 8.0.0.20160204: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( C.hs, interpreted ) Ok, modules loaded: Main. *Main> :k T Type Int T Type Int :: * *Main> :k T Star Int <interactive>:1:3: error: • Data constructor ‘Star’ cannot be used here (Perhaps you intended to use DataKinds) • In the first argument of ‘T’, namely ‘Star’ In the type ‘T Star Int’ }}} Of course, if we pass `-TypeInType` to GHCi that fixes the problem (BTW, `DataKinds` does NOT solve the problem.) -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11964#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#11964: Without TypeInType, inconsistently accepts Data.Kind.Type but not type synonym -------------------------------------+------------------------------------- Reporter: ezyang | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.0.1-rc2 checker) | Resolution: | Keywords: TypeInType 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 goldfire): * keywords: => TypeInType -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11964#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#11964: Without TypeInType, inconsistently accepts Data.Kind.Type but not type synonym -------------------------------------+------------------------------------- Reporter: ezyang | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.0.1-rc2 checker) | Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Interestingly, I can't reproduce this issue on GHC 8.0.1 or later, so perhaps this issue only existed in the GHC 8.0.1 release candidates? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11964#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#11964: Without TypeInType, inconsistently accepts Data.Kind.Type but not type
synonym
-------------------------------------+-------------------------------------
Reporter: ezyang | Owner: goldfire
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler (Type | Version: 8.0.1-rc2
checker) |
Resolution: | Keywords: TypeInType
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by Ryan Scott
#11964: Without TypeInType, inconsistently accepts Data.Kind.Type but not type synonym -------------------------------------+------------------------------------- Reporter: ezyang | Owner: goldfire Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler (Type | Version: 8.0.1-rc2 checker) | Resolution: fixed | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | dependent/should_run/T11964 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => closed * testcase: => dependent/should_run/T11964 * resolution: => fixed -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11964#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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