[GHC] #14131: Difference between newtype and newtype instance
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 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: -------------------------------------+------------------------------------- This works {{{#!hs {-# Language RankNTypes, PolyKinds, GADTs #-} newtype Nat :: (k -> *) -> (k -> *) -> * where Nat :: (forall xx. f xx -> g xx) -> Nat f g }}} but this {{{#!hs {-# Language RankNTypes, PolyKinds, GADTs, TypeFamilies #-} data family Nat :: k -> k -> * newtype instance Nat :: (k -> *) -> (k -> *) -> * where Nat :: (forall xx. f xx -> g xx) -> Nat f g }}} fails on GHC 8.3.20170815, and requires a `forall k.` to work {{{ $ ./ghc-stage2 -ignore-dot-ghci --interactive /tmp/kind.hs GHCi, version 8.3.20170815: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( /tmp/kind.hs, interpreted ) /tmp/kind.hs:5:26: error: Not in scope: type variable ‘k’ | 5 | newtype instance Nat :: (k -> *) -> (k -> *) -> * where | ^ /tmp/kind.hs:5:38: error: Not in scope: type variable ‘k’ | 5 | newtype instance Nat :: (k -> *) -> (k -> *) -> * where | ^ Failed, 0 modules loaded. }}} Related to #12369? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies 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): * cc: RyanGlScott (added) * keywords: => TypeFamilies -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies 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): No. Not really related to #12369. Perhaps related to #13985. Perhaps not. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies 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): Note that this error does not occur if the kind variables are bound in an earlier type pattern. That is, this equivalent instance typechecks: {{{#!hs {-# LANGUAGE GADTs #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE TypeFamilies #-} data family Nat :: k -> k -> * newtype instance Nat (f :: k -> *) :: (k -> *) -> * where Nat :: (forall xx. f xx -> g xx) -> Nat f g }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies 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): After tinkering around with this example some more, I realized that the problem isn't limited to just data family instances—this affects type families across the board. Namely, type families do not implicitly bind kind variables that users write in result signatures. That is, this type synonym definition is legal: {{{#!hs {-# LANGUAGE DataKinds #-} {-# LANGUAGE PolyKinds #-} type F = (Nothing :: Maybe a) }}} But this type family instance is not legal: {{{#!hs {-# LANGUAGE DataKinds #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE TypeFamilies #-} type family F :: Maybe a type instance F = (Nothing :: Maybe a) }}} {{{ GHCi, version 8.3.20170816: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Main ( Bug.hs, interpreted ) Bug.hs:6:37: error: Not in scope: type variable ‘a’ | 6 | type instance F = (Nothing :: Maybe a) | ^ }}} I don't see any reason why the latter definition should be rejected. One could object that all the type variables in a type family instance must be bound on the LHS type patterns. But really, the `a` is `Maybe a` is bound by the often-neglected //RHS// type pattern. This is made more evident by the fact that tweaking the code to avoid the explicit `Maybe a` kind ascription makes it typecheck: {{{#!hs type instance F = Nothing }}} However, if you inspect `F` with `:info` in GHCi with the `-fprint- explicit-kinds` flag enabled, then you discover that you end up achieving the same result in the end: {{{ λ> :set -fprint-explicit-kinds λ> :i F type family F a :: Maybe a -- Defined at Bug.hs:5:1 type instance F a = 'Nothing a -- Defined at Bug.hs:6:15 }}} Here, it becomes evident that the kind variable `a` in `Maybe a` is being implicitly bound. But alas, GHC won't let you write it out explicitly. This becomes even more infuriating when dealing with associated type instances. For example, I tried to write this: {{{#!hs {-# LANGUAGE DataKinds #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE TypeFamilies #-} class C k where type T :: k instance C (Maybe a) where type T = (Nothing :: Maybe a) }}} {{{ GHCi, version 8.3.20170816: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Main ( Bug.hs, interpreted ) Bug.hs:9:3: error: The RHS of an associated type declaration mentions ‘a’ All such variables must be bound on the LHS | 9 | type T = (Nothing :: Maybe a) | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ }}} Once again, GHC mistakenly assumes that `a` must be bound in a LHS type pattern. But the whole point of `T` is that the instance is determined by the RHS type pattern! So as a workaround, I must leave off the explicit kind signature. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies 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): Good sleuthing here. Do you think you can fix the bug? I don't think it would be too hard. My guess is that fixing this in concert with #13985 will work nicely. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #13985 | Differential Rev(s): Phab:D3872 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => patch * differential: => Phab:D3872 * related: => #13985 Comment: Replying to [comment:5 goldfire]:
Do you think you can fix the bug?
You got it! See Phab:D8372, which also fixes #13985 and #13988. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872 #13985 | Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * related: #13985 => #7938, #9574, #13985 Comment: It's also worth noting that Phab:D3872 reverses a design decision made in #7938 and #9574 to only allow kind variables in the RHSes of associated type instances if they're explicitly bound by LHS type patterns. But I think this is the right thing to do, because otherwise you can't have things like: {{{#!hs class C k where data family Nat :: k -> k -> Type instance C (k -> Type) where newtype Nat :: (k -> Type) -> (k -> Type) -> Type where Nat :: (forall xx. f xx -> g xx) -> Nat f g }}} And rejecting this feels like the wrong stance to take. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872 #13985 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj):
It's also worth noting that Phab:D3872 reverses a design decision made in #7938 and #9574 to only allow kind variables in the RHSes of associated type instances if they're explicitly bound by LHS type patterns.
But really, the a is Maybe a is bound by the often-neglected RHS type
I don't think it reverses it. We just didn't implement it properly. If we wrote out the kind arguments we'd see {{{ class C k where data family Nat @k :: k -> k -> Type instance C (k -> Type) where newtype Nat @(k -> Type) :: (k -> Type) -> (k -> Type) -> Type where Nat :: forall k (f::k->Type) (g::k->Type). (forall xx. f xx -> g xx) -> Nat @(k->Type) f g }}} So that `k` certainly is bound on the left, in the (invisible) kind pattern. pattern. I don't like this language. There is no "RHS type pattern". Rather, there are invisible kind patterns on the LHS. And this matters! Consider {{{ type family T (a :: Type) :: Type type family F :: k type instance T Int = Proxy (F :: k) }}} Now `T` does not have a kind parameter, and that `k` on the RHS of the `type instance` really is unbound. Writing out the kind arguments: {{{ type instance T Int = Proxy @k (F @k) }}} which is manifestly wrong. '''Bottom line''': we can't distinguish the two cases in the renamer. We have to check this in the type checker. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872 #13985 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): I'm not happy with Phab:D3872. Currently we have {{{ type HsTyPats pass = HsImplicitBndrs pass [LHsType pass] }}} That sugggests that the implicit binders scope only over the patterns. But as we know, they don't. They scope over the RHS too. And indeed, as this ticket discusses, we may have variables that are implicitly bound in the RHS, but are not even mentioned on the LHS. These `HsTyPats` are used in `DataFamInstDecl` and `TyFamInstEqn` (only). For the latter: Currently we have {{{ type TyFamInstEqn pass = TyFamEqn pass (HsTyPats pass) type TyFamDefltEqn pass = TyFamEqn pass (LHsQTyVars pass) data TyFamEqn pass pats = TyFamEqn { tfe_tycon :: Located (IdP pass) , tfe_pats :: pats , tfe_fixity :: LexicalFixity -- ^ Fixity used in the declaration , tfe_rhs :: LHsType pass } }}} where the implicit binders inside `tfe_pats` weirdly scopes over the `tfe_rhs`. Instead we can have {{{ type TyFamInstEqn pass = HsImplicitBndrs (TyFamEqn pass [HsType pass]) type TyFamDefltEqn pass = HsImplicitBndrs (TyFamEqn pass [LHsTyVarBndr pass]) }}} I have not worked through the details, but it seems right to wrap the implicit binders around everything that they scopes over. I suspect that'll make the code easier too. It's similar for `DataFamInstDecl`. Currently we have: {{{ data DataFamInstDecl pass = DataFamInstDecl { dfid_tycon :: Located (IdP pass) , dfid_pats :: HsTyPats pass , dfid_fixity :: LexicalFixity , dfid_defn :: HsDataDefn pass , dfid_fvs :: PostRn pass NameSet } }}} Instead we could have {{{ type DataFamInstDecl pass -- Implicit bndrs here = HsImplicitBndrs pass (DataFamInstEqn pass) data DataFamInstEqn pass = DataFamInstEqn { dfid_tycon :: Located (IdP pass) , dfid_pats :: [LHsType pass] -- No implicit bndrs , dfid_fixity :: LexicalFixity , dfid_defn :: HsDataDefn pass , dfid_fvs :: PostRn pass NameSet } }}} Bubt that's still a bit strange, because the `dfid_fvs` should really be outside the `HsImplicitBndrs`. (And it is for `TyFamEqn`. So perhaps a better way would be to make `DataFamInstDecl` and `TyFamInstDecl` look a bit more like each other, thus {{{ type DataFamInstDecl pass = FamInstDecl pass (HsDataDefn pass) type TyFamINstDecl pass = FamInstDecl pass (LHsType pass) data FamInstDecl pass rhs = FamInstDecl { fid_eqn :: LFamInstEqn pass rhs , fid_fvs :: PostRn pass NameSet } type LFamInstEqn pass rhs = Located (FamInstEqn pass rhs) type FamInstEqn pass rhs = HsImplicitBndrs (FamEqn pass [LHsType] rhs) data FamEqn pass pats rhs = TyFamEqn { tfe_tycon :: Located (IdP pass) , tfe_pats :: pats , tfe_fixity :: LexicalFixity , tfe_rhs :: rhs } }}} We still need the typechecker test for comment:8. Finally: we need user-manual comments to explain what's accepted and what is rejected. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: RyanGlScott Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872 #13985 | Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * owner: (none) => RyanGlScott Comment: The refactoring suggested in comment:9 sounds good to me. But perhaps I should first do this refactoring in a separate commit, since doing all of this datatype reshuffling and fixing the bugs in #14131 and #13985 simultaneously might be a touch too much. Replying to [comment:9 simonpj]:
We still need the typechecker test for comment:8.
Phab:D3872 has this in the form of the `testsuite/tests/polykinds/T13985.hs` test.
Finally: we need user-manual comments to explain what's accepted and what is rejected.
Phab:D3872 has this already. Done. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: RyanGlScott Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872 #13985 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj):
We still need the typechecker test for comment:8.
What I mean is: the renaner cannot reject the right set of programs (see comment:8). So the renamer must err on the side of acceptance, and leave the type checker to reject programs where variables appear on the RHS that are not bound on the left.
But perhaps I should first do this refactoring in a separate commit
Sounds good to me. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
What I mean is: the renaner cannot reject the right set of programs (see comment:8). So the renamer must err on the side of acceptance, and leave
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: RyanGlScott Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872 #13985 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Replying to [comment:11 simonpj]: the type checker to reject programs where variables appear on the RHS that are not bound on the left. Right, this is exactly what Phab:D3872 is doing at the moment. In particular, it changes `TcTyClsDecls` so that we check for free-floating kind variables (or, as you put it, variables that appear on the RHS that are not bound on the left) when typechecking family instances. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: RyanGlScott Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872 #13985 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Really? `reportFloatingKvs` seems to report variables mentioned in `typat_tvs`, which doesn't look like the ones on the RHS. I wasn't expecting a test in `tcFamTyPats`, but rather in `tcTyFamInstEqn`. DO you have a test like the example in comment:8? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: RyanGlScott Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872 #13985 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Replying to [comment:13 simonpj]:
Really? `reportFloatingKvs` seems to report variables mentioned in `typat_tvs`, which doesn't look like the ones on the RHS. I wasn't expecting a test in `tcFamTyPats`, but rather in `tcTyFamInstEqn`.
Ah, I think I managed to confuse you by naming that variable `typat_tvs`. Those are the type variables that are used in type patterns (visible and invisible) //or// the RHS (these are collected during renaming, see `rnFamInstDecl`). We discover in `tcFamTyPats` which variables are actually bound by type patterns, so if there are any used variables that aren't bound, then they're free-floating (and summarily rejected). I suppose I should rename `typat_tvs` to something like `fam_used_tvs` to avoid this confusion.
DO you have a test like the example in comment:8?
Yes, see `testsuite/tests/polykinds/T13985.hs`. In the particular case of type family instances, it tests this: {{{#!hs type instance T = Proxy (Nothing :: Maybe a) }}} Which is rejected for having a free-floating `a`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: RyanGlScott Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872 #13985 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj):
Ah, I think I managed to confuse you
I am indeed terribly confused. I can now just about see what you are doing. * The `hsib_vars` wrapped around the `HsTyPats` includes (via the renamer) the variables mentioned in the RHS. You arrange that `tc_fam_ty_pats` returns them to its caller. * Now in `tcFamTyPats` you can take that set of variables, and subtract from it those bound on the LHS (gotten from the free vars of the typechecked pates). Result is the ones on the RHS but not LHS. Ugh! I bet that all this will look different, and much more perspicous, once we've done the refactoring in comment:9. As you suggest, let's do that first. Yell if you need any help -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: RyanGlScott Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872, #13985 | Phab:D3881 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * differential: Phab:D3872 => Phab:D3872, Phab:D3881 Comment: I took a go at the suggested refactoring in comment:9 at Phab:D3881. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:16 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance
-------------------------------------+-------------------------------------
Reporter: Iceland_jack | Owner: RyanGlScott
Type: bug | Status: patch
Priority: normal | Milestone:
Component: Compiler | Version: 8.2.1
Resolution: | Keywords: TypeFamilies
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872,
#13985 | Phab:D3881
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by Ben Gamari
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872, #13985 | Phab:D3881 Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * owner: RyanGlScott => (none) * status: patch => new Comment: I believe more work is needed to fix the actual bug here. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:18 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: RyanGlScott Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872, #13985 | Phab:D3881 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * owner: (none) => RyanGlScott Comment: Replying to [comment:18 bgamari]:
I believe more work is needed to fix the actual bug here.
Indeed there is. I'll work on polishing up Phab:D3872 and fixing this ticket for good. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:19 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: RyanGlScott Type: bug | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872, #13985 | Phab:D3881 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => patch Comment: Phab:D3872 is ready for review. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:20 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#14131: Difference between newtype and newtype instance
-------------------------------------+-------------------------------------
Reporter: Iceland_jack | Owner: RyanGlScott
Type: bug | Status: patch
Priority: normal | Milestone:
Component: Compiler | Version: 8.2.1
Resolution: | Keywords: TypeFamilies
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: 13988 | Blocking:
Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872,
#13985 | Phab:D3881
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by Ryan Scott
#14131: Difference between newtype and newtype instance -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: RyanGlScott Type: bug | Status: closed Priority: normal | Milestone: 8.4.1 Component: Compiler | Version: 8.2.1 Resolution: fixed | Keywords: TypeFamilies Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: indexed- | types/should_compile/T14131 Blocked By: 13988 | Blocking: Related Tickets: #7938, #9574, | Differential Rev(s): Phab:D3872, #13985 | Phab:D3881 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * testcase: => indexed-types/should_compile/T14131 * status: patch => closed * resolution: => fixed * milestone: => 8.4.1 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14131#comment:23 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
participants (1)
-
GHC