从模块重新导出功能

Question

我有一个像这样的模块

module A where

import qualified Data.Maybe as Maybe

fromMaybe = Maybe.fromMaybe

是否可以仅从Data.Maybe中重新导出某些功能？我不想重新导出整个Data.Maybe模块，而只是重新导出某些功能，例如fromMaybe。

Answer 1

是的，您可以有选择地重新导出功能：

module A (
  module A,
  Maybe.fromMaybe ) where 

import qualified Data.Maybe as Maybe

模块定义后()中的片段定义了要导出的内容。这里我们说“将所有module A连同函数Maybe.fromMaybe一起导出。”