Amazonka的Lens来处理错误,但我很难处理错误: doSignup e p = (AWS.send $ AWS.signUp "secret" e p) & catching_UsernameExistsException (return $ Left AlreadyExistingEmail) & <em
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val x1 = catching(classOf[MalformedURLException]) opt new URL(s)
val x2 = catching(classOf[MalformedURLException], classOf[NullPointerException]) either new URL(s