Haskell: makeLenses - 数据构造函数不在范围内

Question

我这里有这个简单的代码来定义类型并使用 makeLenses 生成镜头。

module Api.Jira.Types.Search
  (
    SearchRequest(..)
  ) where

import GHC.Generics
import qualified Data.Text as T
import Data.Aeson (FromJSON, ToJSON)
import Control.Lens
import Data.Aeson
import Data.Aeson.Types

data SearchRequest = SearchRequest
  { _jql :: T.Text
  , _startAt :: Maybe Int
  , _maxResults :: Maybe Int
  , _fields :: Maybe [T.Text]
  , _expand :: Maybe [T.Text]
  , _properties :: Maybe [T.Text]
  } deriving (Show, Generic)

instance ToJSON SearchRequest where
  toJSON = genericToJSON defaultOptions {
             fieldLabelModifier = drop 1 }

instance FromJSON SearchRequest where
  parseJSON = genericParseJSON defaultOptions {
                fieldLabelModifier = drop 1 }

makeLenses SearchRequest''

这会导致错误：

Data constructor not in scope: SearchRequest'' :: template-haskell-2.11.1.0:Language.Haskell.TH.Syntax.Name • Perhaps you meant one of these: ‘SearchRequest’ (line 20), variable ‘searchRequest’ (line 39)

我在 SO 上发现了两个有点相关的问题，但它们与声明顺序有关并且似乎不适用于此处，因为 SearchRequest 中包含的所有类型都已定义。

Haskell: Template Haskell and the scope

知道是什么原因造成的吗？

Answer 1

是''SearchRequest，不是SearchRequest''。

Haskell: makeLenses - 数据构造函数不在范围内

Haskell: makeLenses - data constructor not in scope

haskell

template-haskell