Beefy Boxes and Bandwidth Generously Provided by pair Networks
Clear questions and runnable code
get the best and fastest answer
 
PerlMonks  

Re^3: Is there any way to override "file test operator"?

by Marshall (Canon)
on Mar 21, 2018 at 03:37 UTC ( #1211391=note: print w/replies, xml ) Need Help??


in reply to Re^2: Is there any way to override "file test operator"?
in thread Is there any way to override "file test operator"?

I read back through this thread. Now that I see it again, the question appears to be "how can I make new file test operator?".
I don't know how to do that.

Overriding an existing file operator (like: -e $filename) is very bad idea. I stick to that opinion. The issue is when I see a line like that in some huge amount of code, I expect -e to do what it normally does without having to read any previous code that redefined that operation. And BTW, I don't know how to redefine -e either.

In this case, I would make a subroutine that did the desired test and use that. In terms of execution efficiency, I see no difference. In terms of source code, there would be a huge increase in clarity.

  • Comment on Re^3: Is there any way to override "file test operator"?

Replies are listed 'Best First'.
Re^4: Is there any way to override "file test operator"?
by QM (Parson) on Mar 21, 2018 at 11:48 UTC
    The benefit of overloading it, is that existing code "does the right thing", given whatever the new underlying context is, everyone can use the old idioms, even though they aren't quite the same.

    In fact, a good overload would not lose functionality on normal arguments. For instance, what if someone wanted to instrument logging by absolute filename, to collect statistics? Extending -e to do this would be easier than replacing every file test operator call everywhere, including external packages.

    For these kinds of questions, it's better if we get a real sense of the OP's ultimate goal and purpose, before declaring "that's a bad idea" just because it usually is.

    -QM
    --
    Quantum Mechanics: The dreams stuff is made of

Re^4: Is there any way to override "file test operator"?
by Anonymous Monk on Jul 07, 2018 at 19:57 UTC

    -e is broken on windows, it doesn't do unicode

    Win32::Unicode does do unicode , but it can't override -e

    So win32 people can't use -e on win32

    You're still not authority on what should or should not be done

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1211391]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others imbibing at the Monastery: (7)
As of 2021-04-16 07:33 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found

    Notices?