#10704: Can't lookup fixities of infix types in Template Haskell -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 7.10.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by RyanGlScott): Sorry, I forgot to mention that I was using the HEAD version of GHCi, in which it does work (after fixing #10018): {{{ $ inplace/bin/ghc-stage2 --interactive -XTypeOperators -XTypeFamilies -XMultiParamTypeClasses GHCi, version 7.11.20150727: http://www.haskell.org/ghc/ :? for help λ> class a :=> b; infixr 5 :=> λ> :i :=> class (:=>) a b -- Defined at <interactive>:1:1 infixr 5 :=> λ> type a :+: b = Either a b; infixr 5 :+: λ> :i :+: type (:+:) a b = Either a b -- Defined at <interactive>:3:1 infixr 5 :+: λ> type family a :*: b; infixr 5 :*: λ> :i :*: type family (:*:) a b :: * -- Defined at <interactive>:5:1 infixr 5 :*: }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10704#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10704: Can't lookup fixities of infix types in Template Haskell -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: | RyanGlScott Type: feature request | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Changes (by RyanGlScott): * owner: => RyanGlScott -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10704#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10704: Can't lookup fixities of infix types in Template Haskell -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: | RyanGlScott Type: feature request | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: Phab:D1109 -------------------------------------+------------------------------------- Comment (by goldfire): Now that this is done (see Phab:D1109 -- many thanks!), it looks like it could all be refactored a little more cleanly. What about {{{ module TH.Syntax where ... class ... => Quasi q where ... qReifyFixity :: Name -> q Fixity reifyFixity :: Name -> Q Fixity }}} and then remove all of the `Fixity` fields in `Info`? This should not be a hard change to deal with downstream, and it would declutter things somewhat. It's true that `TyVarI` doesn't have fixities (although they should, morally, except that Haskell provides no way of giving a fixity specification to a type variable), but `PrimTyConI` ''can'' have a fixity: `(->)` has hard-wired fixity `infixr 0`. I'm not wedded to this change, but I do think it's an improvement. Speak up if you have a strong opinion! -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10704#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10704: Can't lookup fixities of infix types in Template Haskell -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: | RyanGlScott Type: feature request | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: Phab:D1109 -------------------------------------+------------------------------------- Comment (by RyanGlScott): You're right, a {{{Quasi}}}-based approach would be way cleaner. I'll update Phab:D1109 to incorporate that. I have one more question about fixities of {{{PrimTyConI}}}, though. It makes sense that {{{(->)}}} has a fixity, now that I actually think about it, but what about prefix types like {{{Char#}}}? Would these always have be {{{infixl 9}}}? If so, should calling {{{qReifyFixity}}} on a {{{TyVarI}}} also yield {{{Fixity 9 InfixL}}}? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10704#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10704: Can't lookup fixities of infix types in Template Haskell -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: | RyanGlScott Type: feature request | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: Phab:D1109 -------------------------------------+------------------------------------- Comment (by RyanGlScott):

You'll probably have to deal with (->) specially (use BasicTypes.funTyFixity), but I think that will be the only special case.

I was wondering if that was the case, since running {{{:i (->)}}} in GHCi doesn't tell what its fixity is. For that matter, {{{:i (~)}}} doesn't work in GHCi either... I should probably open a separate ticket for this. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10704#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10704: Can't lookup fixities of infix types in Template Haskell -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: | RyanGlScott Type: feature request | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 7.10.1 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: Phab:D1109 -------------------------------------+------------------------------------- Comment (by Ben Gamari ): In [changeset:"575abf42e218925e456bf765abb14f069ac048a0/ghc" 575abf42/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="575abf42e218925e456bf765abb14f069ac048a0" Add Fixity info for infix types Template Haskell allows reification of fixity for infix functions and data constructors, and not for infix types. This adds a `Fixity` field to the relevant `Info` constructors that can have infix types (`ClassI`, `TyConI`, and `FamilyI`). I don't think that `VarI` or `PrimTyConI` can be infix, but I could be wrong. Test Plan: ./validate Reviewers: austin, goldfire, bgamari Reviewed By: goldfire, bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1109 GHC Trac Issues: #10704 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10704#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler