错误定义模板haskell函数

Question

我开始学习模板haskell，所以我想创建一个接收String参数的函数，该参数定义要生成的函数的名称

build_p5 :: String -> [Dec]
build_p5 name =
[ FunD p1 
         [ Clause [TupP [VarP a,VarP b]] (NormalB (AppE (VarE c) (VarE a))) [FunD c [Clause [VarP a] (NormalB (VarE a)) []]]
         ]
] where
   p1 = mkName name
   a = mkName "a"
   b = mkName "b"
   c = mkName "ident"

运行定义：

$(build_p5 "hola")

但是当我运行该程序时会出现以下错误

Couldn't match type ‘[Dec]’ with ‘Q [Dec]’
Expected type: DecsQ
  Actual type: [Dec]
In the expression: build_p5 "hola"

正确的代码

build_p2 :: Monad m => String -> m [Dec]
build_p2 name =
return [ FunD p1 
     [ Clause [TupP [VarP a,VarP b]] (NormalB (AppE (VarE c) (VarE a))) [FunD c [Clause [VarP a] (NormalB (VarE a)) []]]
     ]
  ] where
  p1 = mkName name
  a = mkName "a"
  b = mkName "b"
  c = mkName "ident"