Re^3: scope of "use strict"? (needed: "superstrict")

in reply to Re^2: scope of "use strict"? (needed: "superstrict")
in thread scope of "use strict"? (needed: "superstrict")

You're missing my point. If the code was written without strictures, you cannot add them without rewriting the code. You're just as likely to introduce new bugs in doing so.

Take this overly simple example:

sub blarg {
    $i = $i+1;
    return $i;
}
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Now, if you think "there's somethng wrong with this code, I'm going to fix it by adding strictures," then your first step would be:

use strict;
sub blarg {
    $i = $i+1;
    return $i;
}
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Now this will give you errors (use of undefined variable $i). AHA! you say, I'll fix this by declaring $i at the scope at which it is used:

use strict;
sub blarg {
    my $i = $i+1;
    return $i;
}
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Problem solved, strict warnings are gone. Only now your code is completely and totally broken, because little did you know that blarg() was a sequence generator. $i should have been declared at a broader scope than you did. Notice that your change was not syntactically incorrect, but it was semantically incorrect.

Another option would be just to declare every variable used in the entire program at as wide a scope as possible, but that would completely defeat the purpose of strictures, all together.

Last is to try to write something which goes through and adds in a my $var at the "right" scope. The problem with that, however, is that in the general case it is equivalent to The Halting Problem, i.e., writing a program that can analyze and understand the execution of another program, and it is provably IMPOSSIBLE. (Before anyone jumps on me about that being a false statement, about run-time versus structure, I just have one thing to say to you: eval.)

In the end, code written with strictures is DIFFERENT CODE than code written without strictures. Turning strictures on in code that was written without them will just make things worse (unless you plan on REWRITING the code, COMPLETELY). What you're asking for is tantamount to something like: "Well I think that Java is easier to debug than Perl, so I'll take my perl code and run it through a java compiler." All it will do is produce red-herring errors, and tell you nothing about why your code is not doing what you want. Sorry.

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