bad-th.hs

-- decls :: [Decl]
-- makeTables :: [Decl] -> Tables

quoteDeclarations :: String -> ExpQ
quoteDeclarations str = do
  loc <- TH.location
  Right decls <- pure $ runTokenParse parseDecls str
  
  -- Antiquotation: must run before `makeTables`
  let decls' = dataToExpQ (const Nothing `extQ` replaceVars) decls

  -- problem here:
  --  • GHC stage restriction:
  --      ‘decls'’ is used in a top-level splice, quasi-quote, or annotation,
  --      and must be imported, not defined locally
  --  • In the untyped splice: $decls'
  let tables = makeTables $(decls')
  dataToExpQ
    (const Nothing `extQ` handleByteString `extQ` handleText)
    tables