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[GHC] #11210: Missing instances for Identity and Const
by GHC 22 Dec '15

22 Dec '15

#11210: Missing instances for Identity and Const -------------------------------------+------------------------------------- Reporter: duairc | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: | Version: 7.11 libraries/base | Keywords: g | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The following instances are all permissible yet are not defined. They can all be derived with {{{GeneralizedNewtypeDeriving}}}. It would be useful for me if they were defined in {{{base}}}. These should probably also go into {{{base-orphans}}} and {{{transformers}}} (for versions of {{{base}}} before {{{Identity}}} was moved there). {{{#!hs instance Bounded a => Bounded (Const a b) instance Enum a => Bounded (Const a b) instance Ix a => Bounded (Const a b) instance Semigroup a => Semigroup (Const a b) instance Bounded a => Bounded (Identity a) instance Enum a => Bounded (Identity a) instance Ix a => Bounded (Identity a) instance Semigroup a => Semigroup (Identity a) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11210> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #1311: newtypes of unboxed types disallowed - documentation bug and/or feature request
by GHC 22 Dec '15

22 Dec '15

#1311: newtypes of unboxed types disallowed - documentation bug and/or feature request -------------------------------------+------------------------------------- Reporter: Isaac Dupree | Owner: osa1 Type: feature request | Status: new Priority: low | Milestone: ⊥ Component: Compiler | Version: 7.7 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 goldfire): I think this will be quite easy, actually. You're hunting in all the right places. `getInitialKind` does indeed assume a result of kind `*`. (A kind sig ''can'' be provided via `newtype Blah :: * -> * where ...` as if you're defining a GADT. That is, GADT syntax works with newtypes just fine.) But I don't think anyone gets hurt if you assume that the return kind is `TYPE v` for a fresh levity metavariable `v`. You may need to unify that result kind with `*` in the datatype case somewhere. You'd need to check that the result kind of the newtype matches the kind of the representation type. I think this would happen in `kcConDecl`. One annoying bit is that we have no surface syntax (other than `TYPE 'Unlifted`) for `#`. I suppose you could add `type UnliftedType = TYPE 'Unlifted` in `Data.Kind` if you felt it worthwhile. I really don't think it would be much harder than this. Go for it! :) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1311#comment:11> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10828: TH can't represent all GADTs in its AST
by GHC 22 Dec '15

22 Dec '15

#10828: TH can't represent all GADTs in its AST -------------------------------------+------------------------------------- Reporter: spinda | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: Template | Version: 7.10.2 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- For example, it's impossible to add a kind signature on a data type with `DataD`. In {{{Con}}} I believe it's possible to encode GADT constructor signatures using {{{NormalC}}} (haven't tried this yet), but ideally there would be another constructor specific to GADTs to go along with {{{RecC}}}, {{{InfixC}}}, and {{{ForallC}}}. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10828> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11270: "Unusable UNPACK pragma" warnings should be printed even without -O
by GHC 22 Dec '15

22 Dec '15

#11270: "Unusable UNPACK pragma" warnings should be printed even without -O -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 7.11 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: -------------------------------------+------------------------------------- UNPACK pragmas are ignored when -O is not used, and this is very annoying when developing inside GHCi. Example: {{{ ➜ unpack_warning ghc-stage2 Main.hs -Wall -fforce-recomp --make [1 of 1] Compiling Main ( Main.hs, Main.o ) Linking Main ... }}} No warning printed even though I used {{{-Wall}}}. If I add {{{-O}}}: {{{ ➜ unpack_warning ghc-stage2 Main.hs -Wall -fforce-recomp --make -O [1 of 1] Compiling Main ( Main.hs, Main.o ) Main.hs:5:13: warning: • Ignoring unusable UNPACK pragma on the first argument of ‘Blah’ • In the definition of data constructor ‘Blah’ In the data type declaration for ‘Blah’ Linking Main ... }}} This is very annoying, because {{{-O}}} is ignored in GHCi: {{{ ➜ unpack_warning ghc-stage2 Main.hs -Wall -fforce-recomp -O --interactive when making flags consistent: warning: -O conflicts with --interactive; -O ignored. GHCi, version 7.11.20151220: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( Main.hs, interpreted ) Ok, modules loaded: Main. }}} So basically there's no way to get these warning in GHCi. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11270> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11264: Previously compiling example does not compile
by GHC 22 Dec '15

22 Dec '15

#11264: Previously compiling example does not compile -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 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: -------------------------------------+------------------------------------- -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11264> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #1311: newtypes of unboxed types disallowed - documentation bug and/or feature request
by GHC 22 Dec '15

22 Dec '15

#1311: newtypes of unboxed types disallowed - documentation bug and/or feature request -------------------------------------+------------------------------------- Reporter: Isaac Dupree | Owner: osa1 Type: feature request | Status: new Priority: low | Milestone: ⊥ Component: Compiler | Version: 7.7 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 osa1): I'd like to give this a try, Richard, where should I start? I don't understand typechecking/ parts too well. As far as I can see, {{{kcTyClGroup}}} is kind checking type declarations, and {{{getInitialKind}}} is generating {{{liftedTypeKind}}} unless a kind signature is given (I don't understand how can kind signatures be used with newtypes, maybe that case is impossible?). Is it possible to do this by just generalizing the current code, instead of adding special cases for newtypes in {{{getInitialKind}}} or {{{kcTyClGroup}}} (or both) ? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1311#comment:10> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #1311: newtypes of unboxed types disallowed - documentation bug and/or feature request
by GHC 22 Dec '15

22 Dec '15

#1311: newtypes of unboxed types disallowed - documentation bug and/or feature request -------------------------------------+------------------------------------- Reporter: Isaac Dupree | Owner: osa1 Type: feature request | Status: new Priority: low | Milestone: ⊥ Component: Compiler | Version: 7.7 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 osa1): * owner: => osa1 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1311#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5296: Add explicit type applications
by GHC 22 Dec '15

22 Dec '15

#5296: Add explicit type applications -------------------------------------+------------------------------------- Reporter: dsf | Owner: goldfire Type: feature request | Status: new Priority: low | Milestone: 8.0.1 Component: Compiler (Type | Version: 7.0.3 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: 1897 | Blocking: 10770 Related Tickets: #4466 | Differential Rev(s): Phab:D1681 Wiki Page: | -------------------------------------+------------------------------------- Changes (by goldfire): * differential: Phab:D1138 => Phab:D1681 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5296#comment:26> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5217: GADT declaration not (yet) handled by Template Haskell
by GHC 22 Dec '15

22 Dec '15

#5217: GADT declaration not (yet) handled by Template Haskell -------------------------------------+------------------------------------- Reporter: Ashley Yakeley | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler (Type | Version: 7.0.3 checker) | Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: th/T5217 Blocked By: | Blocking: Related Tickets: #10828 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by jstolarek): * related: => #10828 Comment: #10828 extends TH syntax to support GADTs without encoding them as normal data types. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5217#comment:2> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4188: Template Haskell support for reifying non-vanilla data constructors
by GHC 22 Dec '15

22 Dec '15

#4188: Template Haskell support for reifying non-vanilla data constructors -------------------------------------+------------------------------------- Reporter: illissius | Owner: illissius Type: feature request | Status: closed Priority: normal | Milestone: Component: Template Haskell | Version: Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: th/T4188 Blocked By: | Blocking: Related Tickets: #10828 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by jstolarek): * related: => #10828 Comment: Note that #10828 adds proper support for representing GADTs in Template Haskell. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4188#comment:7> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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