OpenEuphoria

Re: Exception handling

• Posted by ghaberek (admin) Feb 03, 2023
• 701 views

function isHeDead(driver) { 
  try { 
    var url = driver.Url; 
    return false; 
  catch (E) { 
    return true; 
  } 
} 

In your example, you're fetching the URL property of the driver in order to determine the connection status, correct? If I were writing a Selenium library for Euphoria, I would do the same thing:

function isHeDead( atom driver ) 
 
    -- Selenium_GetUrl() would return a sequence (the URL) 
    -- or an atom (an error code, like ERR_TIMEDOUT). 
 
    object url = Selenium_GetUrl( driver ) 
 
    if atom( url ) then 
        -- we received ERR_TIMEDOUT 
        return FALSE 
    end if 
 
    -- we received "https://..." 
    return TRUE 
end function 

Now I'm not saying try/catch isn't a good thing, but in this example I don't see how the two methods are any different.

You could also try the Go approach, which also doesn't have exceptions and instead returns a value and error code from every function:

function isHeDead( atom driver ) 
 
    -- Selenium_GetUrl() would always return a sequence containing two items: 
    -- [1] a sequence: the URL (on success) or an empty sequence (on error) 
    -- [2] an atom: the error code (on error) or zero (on success) 
 
    atom err 
    sequence url 
 
    {url,err} = Selenium_GetUrl( driver ) 
 
    if err then 
        -- we received {"",ERR_TIMEDOUT} 
        return FALSE 
    end if 
 
    -- we received {"https://...",ERR_OK} 
    return TRUE 
end function 

This approach is more strictly enforced in Go than it would be in Euphoria, but it provides good error handling without exceptions. The multiple assignment feature was added in Euphoria 4.1.

What are you talking about, Bruce? It's your baby! You'll need to raise maintain it yourself.

-Greg