Why should Perl special variables get a pass on that?

If you, as a "former monk" don't understand, then it both explains why you left; and why nothing I could possibly say would make the slightest bit of difference to your perception of this situation.

The key indicator here is your phrase: "Mutating global state is bad."

By which you mean: varying variables with top level scope. is verboten; (by you!)

  1. There is no point in having variables; if you cannot vary them!

    Variables that do not; or are not "permitted" to, vary, are constants.

    (It is this, beyond the performance penalties, that make Readonly a nonsense.)

  2. Every program has a 'top level scope'.

    Choosing to differentiate between "global variables" and "top level, lexical variables" is a sham. A pointless and puerile non-distinction.

    Further, every (useful) program ever written makes some assumptions about ... whatever. This is usually referred to as "configuration".

    So your (bland and uninteresting; unless you bother to follow up with some supporting argument) statement reduces to: is there any legitimate reason for a program to ever override its startup assumptions?

    And fine, if you can sit wherever you are, and hand-on-heart, conclude that there is never a legitimate reason for a program to override its startup assumptions; then you've won the argument.

    But, before you pat yourself on the back consider each of these:

    • Have you never written a program that needed to override the default assumption about what constitutes a newline?

      Eg. A *nix program that used sockets.

    • Have you never written a program that needed (or benefited from) overriding the default value of cwd?

    • Have you never written a program that benefited from overriding the default setting of STDIN, STDOUT or STDERR?

      You've never used the one-arg form of select; nor redirected STDERR to a log file?

    • You've never messed with %INC?

      Eg, used lib?

    • You've never tweaked %ENV?
    • How about installed your own signal handler in %SIG?
    • You've never felt the need to reset $@, $!, $^E, and $? before running code that might influence them; and which you need to make decisions upon the values they might acquire?

If you can say "No" to all of those; then you've both won the argument, and are either a liar; or not a programmer.

Being selective about what functionality you accept as legitimate, and what you personally choose to reject is one thing; attempting to impose your affectations upon the world at large is another.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
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". I knew I was on the right track :)
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re^4: What am I not understanding about $, by BrowserUk
in thread What am I not understanding about $, by Anonymous Monk

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