Question

对于未找到文件的内容，下面代码的基本结构将起作用，但对于此除零的示例，不会捕获异常。人们如何得到除以零的分数？

import Control.Exception.Base
import Data.Array

main = toTry `catch` handler

toTry = do
    print "hi"
    print (show (3 `div` 0))
    print "hi"

handler :: IOError -> IO ()
handler e = putStrLn "bad"

Answer 1

您需要一个捕获ArithException的处理程序，并匹配DivideByZero。

import Control.Exception.Base
import Data.Array

main = toTry `catch` handler

toTry = do
    print "hi"
    print (show (3 `div` 0))
    print "hi"

handler :: ArithException -> IO ()
handler DivideByZero = putStrLn "Divide by Zero!"
handler _ = putStrLn "Some other error..."

如何在Haskell中捕获零误差？

1 个答案: