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
}

目前我的表格如下所示：

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

我目前对以下事实感到非常满意，即每种“奶酪”都需要一种形式（尽管我当然不介意使用动态形式..）。但是，我真的很想摆脱在每种形式中重复“用餐名称”。我可以以某种方式组合这些表格，还是我最终必须选择 Monadic 表格？

Answer 1

你就不能随便转转吗

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)