[GHC] #13920: 自動選擇實例
#13920: 自動選擇實例 -------------------------------------+------------------------------------- Reporter: zaoqi | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 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: -------------------------------------+------------------------------------- https://github.com/zaoqi/U.hs/blob/master/Data/U.hs:{{{#!hs --Copyright (C) 2017 Zaoqi --This program is free software: you can redistribute it and/or modify --it under the terms of the GNU Affero General Public License as published --by the Free Software Foundation, either version 3 of the License, or --(at your option) any later version. --This program is distributed in the hope that it will be useful, --but WITHOUT ANY WARRANTY; without even the implied warranty of --MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the --GNU Affero General Public License for more details. --You should have received a copy of the GNU Affero General Public License --along with this program. If not, see http://www.gnu.org/licenses/. {-# LANGUAGE DataKinds, TypeOperators, KindSignatures, GADTs, MultiParamTypeClasses, FlexibleInstances, FlexibleContexts, AllowAmbiguousTypes, UndecidableInstances, IncoherentInstances, NoMonomorphismRestriction #-} module Data.U ( U(), t, u ) where data U :: [*] -> * where UOne :: x -> U (x : xs) USucc :: U xs -> U (x : xs) class T1 a b where t1 :: (U a) -> (U b) instance T1 a a where t1 = id instance T1 xs (x : xs) where t1 = USucc instance T1 (x : y : xs) (y : x : xs) where t1 (UOne x) = USucc (UOne x) t1 (USucc (UOne x)) = UOne x t1 (USucc (USucc xs)) = USucc (USucc xs) instance T1 xs ys => T1 (x : xs) (x : ys) where t1 (UOne x) = UOne x t1 (USucc xs) = USucc (t1 xs) t = t1 . t1 . t1 . t1 . t1 . t1 . t1 . t1 uone :: a -> U '[a] uone = UOne u x = t (uone x) instance Show x => Show (U '[x]) where show (UOne x) = "(u " ++ showsPrec 11 x ")" instance (Show x, Show (U xs)) => Show (U (x : xs)) where show (UOne x) = "(u " ++ showsPrec 11 x ")" show (USucc xs) = show xs }}} {{{#!hs *Data.U> (u 'c') :: U [Int,Char] <interactive>:12:2: error: • No instance for (T1 a30 '[Int, Char]) arising from a use of ‘u’ • In the expression: (u 'c') :: U '[Int, Char] In an equation for ‘it’: it = (u 'c') :: U '[Int, Char] *Data.U> t1 (uone 'c') :: U [Int,Char] (u 'c') }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13920 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#13920: 自動選擇實例 -------------------------------------+------------------------------------- Reporter: zaoqi | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 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 zaoqi): * version: 8.0.1 => 8.0.2 @@ -1,1 +1,2 @@ - https://github.com/zaoqi/U.hs/blob/master/Data/U.hs:{{{#!hs + https://github.com/zaoqi/U.hs/blob/master/Data/U.hs: + {{{#!hs New description: https://github.com/zaoqi/U.hs/blob/master/Data/U.hs: {{{#!hs --Copyright (C) 2017 Zaoqi --This program is free software: you can redistribute it and/or modify --it under the terms of the GNU Affero General Public License as published --by the Free Software Foundation, either version 3 of the License, or --(at your option) any later version. --This program is distributed in the hope that it will be useful, --but WITHOUT ANY WARRANTY; without even the implied warranty of --MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the --GNU Affero General Public License for more details. --You should have received a copy of the GNU Affero General Public License --along with this program. If not, see http://www.gnu.org/licenses/. {-# LANGUAGE DataKinds, TypeOperators, KindSignatures, GADTs, MultiParamTypeClasses, FlexibleInstances, FlexibleContexts, AllowAmbiguousTypes, UndecidableInstances, IncoherentInstances, NoMonomorphismRestriction #-} module Data.U ( U(), t, u ) where data U :: [*] -> * where UOne :: x -> U (x : xs) USucc :: U xs -> U (x : xs) class T1 a b where t1 :: (U a) -> (U b) instance T1 a a where t1 = id instance T1 xs (x : xs) where t1 = USucc instance T1 (x : y : xs) (y : x : xs) where t1 (UOne x) = USucc (UOne x) t1 (USucc (UOne x)) = UOne x t1 (USucc (USucc xs)) = USucc (USucc xs) instance T1 xs ys => T1 (x : xs) (x : ys) where t1 (UOne x) = UOne x t1 (USucc xs) = USucc (t1 xs) t = t1 . t1 . t1 . t1 . t1 . t1 . t1 . t1 uone :: a -> U '[a] uone = UOne u x = t (uone x) instance Show x => Show (U '[x]) where show (UOne x) = "(u " ++ showsPrec 11 x ")" instance (Show x, Show (U xs)) => Show (U (x : xs)) where show (UOne x) = "(u " ++ showsPrec 11 x ")" show (USucc xs) = show xs }}} {{{#!hs *Data.U> (u 'c') :: U [Int,Char] <interactive>:12:2: error: • No instance for (T1 a30 '[Int, Char]) arising from a use of ‘u’ • In the expression: (u 'c') :: U '[Int, Char] In an equation for ‘it’: it = (u 'c') :: U '[Int, Char] *Data.U> t1 (uone 'c') :: U [Int,Char] (u 'c') }}} -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13920#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#13920: 自動選擇實例 -------------------------------------+------------------------------------- Reporter: zaoqi | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 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: | -------------------------------------+------------------------------------- @@ -57,1 +57,1 @@ - {{{#!hs + {{{ New description: https://github.com/zaoqi/U.hs/blob/master/Data/U.hs: {{{#!hs --Copyright (C) 2017 Zaoqi --This program is free software: you can redistribute it and/or modify --it under the terms of the GNU Affero General Public License as published --by the Free Software Foundation, either version 3 of the License, or --(at your option) any later version. --This program is distributed in the hope that it will be useful, --but WITHOUT ANY WARRANTY; without even the implied warranty of --MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the --GNU Affero General Public License for more details. --You should have received a copy of the GNU Affero General Public License --along with this program. If not, see http://www.gnu.org/licenses/. {-# LANGUAGE DataKinds, TypeOperators, KindSignatures, GADTs, MultiParamTypeClasses, FlexibleInstances, FlexibleContexts, AllowAmbiguousTypes, UndecidableInstances, IncoherentInstances, NoMonomorphismRestriction #-} module Data.U ( U(), t, u ) where data U :: [*] -> * where UOne :: x -> U (x : xs) USucc :: U xs -> U (x : xs) class T1 a b where t1 :: (U a) -> (U b) instance T1 a a where t1 = id instance T1 xs (x : xs) where t1 = USucc instance T1 (x : y : xs) (y : x : xs) where t1 (UOne x) = USucc (UOne x) t1 (USucc (UOne x)) = UOne x t1 (USucc (USucc xs)) = USucc (USucc xs) instance T1 xs ys => T1 (x : xs) (x : ys) where t1 (UOne x) = UOne x t1 (USucc xs) = USucc (t1 xs) t = t1 . t1 . t1 . t1 . t1 . t1 . t1 . t1 uone :: a -> U '[a] uone = UOne u x = t (uone x) instance Show x => Show (U '[x]) where show (UOne x) = "(u " ++ showsPrec 11 x ")" instance (Show x, Show (U xs)) => Show (U (x : xs)) where show (UOne x) = "(u " ++ showsPrec 11 x ")" show (USucc xs) = show xs }}} {{{ *Data.U> (u 'c') :: U [Int,Char] <interactive>:12:2: error: • No instance for (T1 a30 '[Int, Char]) arising from a use of ‘u’ • In the expression: (u 'c') :: U '[Int, Char] In an equation for ‘it’: it = (u 'c') :: U '[Int, Char] *Data.U> t1 (uone 'c') :: U [Int,Char] (u 'c') }}} -- Comment (by bgamari): I spent a few minutes looking at this: It seems like you want `(u 'c') :: U [Int,Char]` to behave like `t1 (uone 'c') :: U [Int,Char]`, but they are quite different. Can you provide some more description of the problem? What does GHC do and how does this differ from what you would want it to do? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13920#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#13920: 自動選擇實例 -------------------------------------+------------------------------------- Reporter: zaoqi | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 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: | -------------------------------------+------------------------------------- Comment (by zaoqi): Replying to [comment:2 bgamari]:
I spent a few minutes looking at this: It seems like you want `(u 'c') :: U [Int,Char]` to behave like `t1 (uone 'c') :: U [Int,Char]`, but they are quite different.
Can you provide some more description of the problem? What does GHC do and how does this differ from what you would want it to do?
{{{#!hs (t1 . t1 . t1 . t1 . t1 . t1 . t1) :: a -> a -- t1 = id t1 :: U '[Char] -> U [Int, Char] -- t1 = USucc t :: U '[Char] -> U [Int, Char] t (uone 'c') :: U [Int,Char] (u 'c') :: U [Int,Char] }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13920#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#13920: 自動選擇實例 -------------------------------------+------------------------------------- Reporter: zaoqi | Owner: (none) Type: feature request | Status: infoneeded Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 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 RyanGlScott): * status: new => infoneeded Comment: I can't tell what your problem is from just a single code snippet. We're not mind-readers - please explain clearly what the issue is! -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13920#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#13920: 自動選擇實例 -------------------------------------+------------------------------------- Reporter: zaoqi | Owner: (none) Type: feature request | Status: infoneeded Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 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: | -------------------------------------+------------------------------------- Comment (by zaoqi): Replying to [comment:4 RyanGlScott]:
I can't tell what your problem is from just a single code snippet. We're not mind-readers - please explain clearly what the issue is! #13950
-- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13920#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#13920: 自動選擇實例 -------------------------------------+------------------------------------- Reporter: zaoqi | Owner: (none) Type: feature request | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Resolution: duplicate | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #13950 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: infoneeded => closed * resolution: => duplicate * related: => #13950 Comment: OK, I'm guessing that #13950 supersedes this issue then. I'll close this issue in favor of that one. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13920#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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