How to catch a divide by zero error in Haskell?

Question

For something like file not found the basic structure of the code below will work, but for this example of division by zero the exception is not caught. How does one catch a divide by zero?

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

You need a handler that catches an ArithException, and matches on 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..."