Beefy Boxes and Bandwidth Generously Provided by pair Networks
go ahead... be a heretic
 
PerlMonks  

Re^22: eval to replace die?

by mithaldu (Monk)
on Oct 09, 2010 at 21:57 UTC ( #864424=note: print w/ replies, xml ) Need Help??


in reply to Re^21: eval to replace die?
in thread eval to replace die?

You cannot correct bad process by over-engineering.
You are right, i cannot. I can merely lessen the chance of others actions based on bad process being a danger and i will gladly do so.
There was no reason to parse the error message. You never did anything with the results of the parsing.
There was a reason, since i did something with the result, which i stated in the second paragraph. The value of the change (positive/negative) determined the direction of the change and based on that a css style which is used to colour the message. This not contrived, but slightly anonymized code i've encountered, written by others.
You think? Read again.
I would like to ask you to look at the original starting post of this node tree and ponder the intent of the message the user is asking the perlmonks about. I am of the opinion that it correlates very closely with what i said.


Comment on Re^22: eval to replace die?
Re^23: eval to replace die?
by BrowserUk (Pope) on Oct 09, 2010 at 23:04 UTC
    The value of the change (positive/negative) determined the direction of the change and based on that a css style which is used to colour the message.

    First observation, if the only purpose of the parsing is to detect positive or negative--the regex was wrong. A simple $message =~ /-/ would probably suffice, and create parity with your exception solution in as much as you could change the datatype of the value without requiring a change in the exception handling mechanism.

    Not that I would advocate that solution, but it demonstrates the contrivance of your example. It conflates two exceptions as one.

    The correct solution for the problem of two different possible errors, is to raise the appropriate of two exceptions. One for less; one for more. Each with a different error number. Then there is no purpose in parsing the error; a simple compare takes the appropriate action.

    I would like to ask you to look at the original starting post

    Out of courtesy, I looked again. And I reached the same conclusions.

    Nothing in the OP requires, nor would benefit from, a structured exception. What corrective action could be taken to correct a failure to retrieve a file? None!

    The only possible action is to report the error and terminate. Whether it be that the file does not exist;, or has the wrong permission; there is no point in trapping the die, when the only reasonable action is to do exactly what die does. And all to satisfy the scurrilous default from perl-critic.

    Recommending moving to using E::C, in order to silence perl-critic, when the only possible action is to (laboriously) emulate exactly what die does, is ...

    (*)Did you do me the courtesy re-reading each evolution of my posts, within the context of the posts to which I replied? (Betting not!)


    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.
      Since you are calling me a liar now i'll not bother further with you, save to point out that with your suggestion to use "=~ /-/" you've only added another possibility for the whole thing to break, which is by adding a spurious "-" to the error message, while a structured exception would still work perfectly fine.

        I did not call you a liar. And I didn't make that suggestion.

        And that's been the trouble right the way through. You read what you want to see; not what I wrote.

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://864424]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others meditating upon the Monastery: (8)
As of 2014-11-25 22:27 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    My preferred Perl binaries come from:














    Results (160 votes), past polls