QuasiQuoter.hs

instance Lift Version where
  lift (Version {..}) = [| Version {..} |]

instance Lift VUnit where
  lift (Digits w) = [| Digits w |]
  lift (Str t) = AppE <$> [| Str . T.pack |] <*> TH.lift (T.unpack t)

qq :: (Text -> Q Exp) -> QuasiQuoter
qq quoteExp' =
  QuasiQuoter
  { quoteExp  = (\s -> quoteExp' . T.pack $ s)
  , quotePat  = \_ ->
      fail "illegal QuasiQuote (allowed as expression only, used as a pattern)"
  , quoteType = \_ ->
      fail "illegal QuasiQuote (allowed as expression only, used as a type)"
  , quoteDec  = \_ ->
      fail "illegal QuasiQuote (allowed as expression only, used as a declaration)"
  }

ver :: QuasiQuoter
ver = qq mkV

mkV :: Text -> Q Exp
mkV t = case version t of
             Left e  -> error . show $ e
             Right v -> lift v

{-
error:
    • Couldn't match type ‘t0 m0’ with ‘Q’
      Expected type: Q Exp
        Actual type: t0 m0 Exp
    • In the expression: lift v
      In a case alternative: Right v -> lift v
      In the expression:
        case version t of
          Left e -> error . show $ e
          Right v -> lift v
    |
137 |              Right v -> lift v

error:
    • Couldn't match expected type ‘m0 Exp’ with actual type ‘Version’
    • In the first argument of ‘lift’, namely ‘v’
      In the expression: lift v
      In a case alternative: Right v -> lift v
    |
137 |              Right v -> lift v

-}