Hello world inspection of haskell data types with template haskell

Templ1.hs

{-# LANGUAGE TemplateHaskell #-}
module Templ1 where
import Language.Haskell.TH
import Templ2

data Person = P {
  name :: String,
  age :: Integer
  }

thisIsData = $(whatIs ''Person)
thisIsConstr = $(whatIs 'P)

main = putStr $(inspData ''Person)

Templ2.hs

{-# LANGUAGE TemplateHaskell #-}
module Templ2 where
import Language.Haskell.TH
import Data.List


-- useful sources:
-- https://hackage.haskell.org/package/template-haskell-2.8.0.0/docs/Language-Haskell-TH.html
-- https://hackage.haskell.org/package/data-lens-template-2.1.3/docs/src/Data-Lens-Template.html#makeLenses
whatIs name = do
  info <- reify name 
  case info of
    (TyConI dec) -> litE $ StringL "Data Declaration"
    (DataConI name typ parentName fixity) -> litE $ StringL "Type Constructor" -- $ show typ
    _ -> fail ("Unsupported name: "++nameBase name)


inspData name = do
  info <- reify name
  inspInfo info
  where
    inspInfo info = 
      case info of
        (TyConI dec) -> --litE $ StringL (show dec) --
          inspDec dec
        _ -> fail ("Unsupported name: "++nameBase name)
    inspDec dec =
      case dec of
        (DataD _ name _ constrs _) -> litE $ StringL $
                                      (unlines $ map
                                       inspConstr constrs)
        _ -> fail $ "Unsupported dec: "++(show dec)
    inspConstr con =
      case con of
        (RecC name varStrictTypes)-> show name ++ " { " ++ (unlines $ intersperse ", " $ map inspVarStrTyp varStrictTypes) ++ " } "
        _ -> fail $ "Unsupported record field"
    inspVarStrTyp (v,_,t) = (nameBase v) ++ " :: " ++ show t