ynowork.hs

type family DataType t = s | s -> t where
  DataType Int32 = "int"
  DataType Text = "text"

asType :: Tagged t String
asType = Tagged $ symbolVal (Proxy :: Proxy (DataType t))

{-
• No instance for (KnownSymbol (DataType t0))
    arising from a use of ‘symbolVal’
• In the second argument of ‘($)’, namely
    ‘symbolVal (Proxy :: Proxy (DataType t))’
  In the expression: Tagged $ symbolVal (Proxy :: Proxy (DataType t))
  In an equation for ‘asType’:
      asType = Tagged $ symbolVal (Proxy :: Proxy (DataType t))
-}