haskell - yesod 中嵌套结构的形式

Question

我有以下类型:

data Cheese = Cheddar Int | Edam String String | Cottage String Int

data Meal = Meal {
      nameOfMeal :: String,
      ... other generic fields
      cheese :: Cheese
}

目前我的表单如下所示:

cheddarForm = renderTable $ construct 
             <$> areq textField "Name of meal" Nothing
             <*> areq intField "Cheddar fat" Nothing
      where 
          construct name fat = Meal name (Cheddar fat)

目前，我对每种类型的“奶酪”都需要一种形式感到非常满意(尽管我当然不介意拥有动态形式..)。然而，我真的很想摆脱在每种形式中重复“膳食名称”。我可以以某种方式组合这些形式，还是我最终必须采用 Monadic 形式？

Answer 1

你就不能绕过去吗

conWithNOM ctr = ctr
    <$> areq textField "Name of meal" Nothing

并针对您的其他表单字段调用它？

cheddarForm = renderTable $ conWithNOM construct
    <*> areq intField "Cheddar fat" Nothing
  where 
      construct name fat = Meal name (Cheddar fat)