[GHC] #1830: Automatic derivation of Lift

[GHC]

#1830: Automatic derivation of Lift
-------------------------------------+-------------------------------------
        Reporter:  guest             |                   Owner:
                                     |  RyanGlScott
            Type:  feature request   |                  Status:  new
        Priority:  normal            |               Milestone:  ⊥
       Component:  Template Haskell  |                 Version:  6.8.1
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:  Phab:D1168
-------------------------------------+-------------------------------------

Comment (by RyanGlScott):

 According to [http://packdeps.haskellers.com/reverse/th-lift packdeps], 32
 libraries immediately depend on `th-lift`. Doing a grep of
 [https://github.com/bitemyapp/hackage-packages hackage-packages] for files
 that contain both {{{Language.Haskell.TH.Syntax}}} and {{{instance Lift
 }}} reveals that these additional libraries define their own {{{Lift}}}
 instances:

 {{{
 persistent-template
 shakespeare
 instant-generics
 yesod-core
 sqlite-simple-typed
 generic-deriving
 Euterpea
 regular
 mysql-simple-typed
 cake3
 lighttpd-conf
 postgresql-simple-typed
 type
 pcre-heavy
 myTestlll
 multirec-alt-deriver
 yesod-routes
 type-level-tf
 debian
 vimus
 named-records
 module-management
 Contract
 grammar-combinators
 groundhog-th
 api-tools
 Webrexp
 Webrexp
 type-level
 web-routes-quasi
 monad-logger
 QuasiText
 ta
 logging-facade
 }}}

 This obviously isn't scientifically rigorous, as there is a chance that
 the {{{instance Lift}}} could be using some other {{{Lift}}}, or that the
 {{{Lift}}} instances in those packages wouldn't be derivable in the first
 place. But this at least gives an approximation of how much impact
 {{{deriving Lift}}} might have.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1830#comment:15>
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