[GHC] #11349: [TypeApplications] Create Proxy-free alternatives of functions in base

[GHC]

#11349: [TypeApplications] Create Proxy-free alternatives of functions in base
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           Reporter:  Iceland_jack      |             Owner:
               Type:  feature request   |            Status:  new
           Priority:  normal            |         Milestone:
          Component:  Core Libraries    |           Version:  7.10.3
           Keywords:  TypeApplications  |  Operating System:  Other
       Architecture:  Unknown/Multiple  |   Type of failure:  None/Unknown
          Test Case:                    |        Blocked By:
           Blocking:                    |   Related Tickets:
Differential Rev(s):                    |         Wiki Page:
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 Now that we have [https://phabricator.haskell.org/D1138 TypeApplications]
 how about we create a Proxy-free version of functions in base that
 currently require it:

 {{{#!hs
 tr :: forall a. Typeable a => TypeRep
 tr = typeRep @Proxy @a Proxy

 symbol :: forall s. KnownSymbol s => String
 symbol = symbolVal @s Proxy

 nat :: forall n. KnownNat n => Integer
 nat = natVal @n Proxy
 }}}

 While we're at it let's use [https://hackage.haskell.org/package/base/docs
 /Numeric-Natural.html Natural] as the value-level representation of Nat,
 avoiding `Maybe` in `someNatVal :: Integer -> Maybe SomeNat`:

 {{{#!hs
 nat :: forall n. KnownNat n => Natural
 nat = natVal @n Proxy

 someNatVal :: Natural -> SomeNat
 someNatVal = ...
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11349>
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