#15961: TH 'Lift' instance for 'NonEmpty' -------------------------------------+------------------------------------- Reporter: fr33domlover | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: 8.6.3 Component: Template Haskell | Version: 8.6.2 Resolution: | Keywords: lift, | instance, nonempty Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Description changed by fr33domlover: Old description:

I was using `deriving Lift` on a data type and the `DeriveLift` extension:

{{{#!hs import Data.List.NonEmpty import Language.Haskell.TH

data T = T (NonEmpty String) Int }}}

and I noticed I couldn't get an automatic instance because `NonEmpty` doesn't have a `Lift` instance. I'm wondering if an instance can be added to the `template-haskell` package (or elsewhere if that isn't the right place? I'm assuming it is because `NonEmpty` is in `base` now)

Since `NonEmpty` has a `Data` instance, I suppose the following would be enough?

{{{#!hs instance Data a => Lift (NonEmpty a) }}}

And without using `Data` it could be:

{{{#!hs nonemptyConName :: Name nonemptyConName = mkNameG DataName "base" "Data.List.NonEmpty" ":|"

instance Lift a => Lift (NonEmpty a) where lift (x :| xs) = do x' <- lift x xs' <- traverse lift xs return $ ConE nonemptyConName `AppE` x' `AppE` xs' }}}

New description: I was using `deriving Lift` on a data type and the `DeriveLift` extension: {{{#!hs import Data.List.NonEmpty import Language.Haskell.TH data T = T (NonEmpty String) Int deriving Lift }}} and I noticed I couldn't get an automatic instance because `NonEmpty` doesn't have a `Lift` instance. I'm wondering if an instance can be added to the `template-haskell` package (or elsewhere if that isn't the right place? I'm assuming it is because `NonEmpty` is in `base` now) Since `NonEmpty` has a `Data` instance, I suppose the following would be enough? {{{#!hs instance Data a => Lift (NonEmpty a) }}} And without using `Data` it could be: {{{#!hs nonemptyConName :: Name nonemptyConName = mkNameG DataName "base" "Data.List.NonEmpty" ":|" instance Lift a => Lift (NonEmpty a) where lift (x :| xs) = do x' <- lift x xs' <- traverse lift xs return $ ConE nonemptyConName `AppE` x' `AppE` xs' }}} -- -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15961#comment:1> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

#15961: TH 'Lift' instance for 'NonEmpty' -------------------------------------+------------------------------------- Reporter: fr33domlover | Owner: (none) Type: feature request | Status: patch Priority: normal | Milestone: 8.6.3 Component: Template Haskell | Version: 8.6.2 Resolution: | Keywords: lift, | instance, nonempty Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D5391 Wiki Page: | -------------------------------------+------------------------------------- Changes (by harpocrates): * status: new => patch * differential: => Phab:D5391 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15961#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

#15961: TH 'Lift' instance for 'NonEmpty' -------------------------------------+------------------------------------- Reporter: fr33domlover | Owner: (none) Type: feature request | Status: closed Priority: normal | Milestone: 8.8.1 Component: Template Haskell | Version: 8.6.2 Resolution: fixed | Keywords: lift, | instance, nonempty Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D5391 Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: patch => closed * resolution: => fixed * milestone: 8.6.3 => 8.8.1 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15961#comment:5> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler