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有没有办法绕IO Double
?我在寻找一个功能:Round IO Double到指定的位数 - Haskell
ownRound :: IO Double -> IO Double
这些单元测试:
ownRound 0.51 == 0.5
ownRound 0.49 == 0.5
ownRound 0.5 == 0.5
ownRound 0.7132 == 0.7
ownRound 0.39 == 0.4
'fmap ::(a - > b) - >(IO a - > IO b)'是可能的。 – AJFarmar
@AJFarmar,是的,我明白了。 – Denis