[Haskell-cafe] How to use Template Haskell build Map?

Hi all, I have below instances: instance PageViewState DiredViewState where instance PageViewState StringViewState where I can use Language.Haskell.Exts.Parser scan above instances got list: typeList :: [Type] typeList = [TyCon (UnQual (Ident "DiredViewState")),TyCon (UnQual (Ident "DiredViewState"))] So question is how to use Template Haskell and above `typeList` build below `Map` at compile-time? tagmap = M.fromList [(typeIdOf StringViewState, Exists (Dict :: PageViewStateDict StringViewState)) ,(typeIdOf DiredViewState, Exists (Dict :: PageViewStateDict DiredViewState))] Thanks! -- Andy