[oak perl] Lexical vs. Package variables

[Jon Seidel, CMC]

>> But now I'm grappling with the *basic* idea of scoping:
>> that you're cordoning off a part of your script with a scoped
>> value so that a variable with an identical name elsewhere
>> in the code is unaffected.

This is absolutely the point -- you've got it. Now just generalize your
thinking about programs to include *large* programs... programs that have
many different subroutines to get the job done. What if you wanted a
simple counter (e.g., $i) to count things during a loop. If you couldn't
localize them, you'd have to use $i1 for the first subroutine, $i2 for the
second subroutine, and so on. With even a moderate-sized system, this can
get to be a real pain and the source of obtuse bugs. I know; a system that
I programmed in many years ago had exactly that problem...

>>
>> This actually seems pointless, if I'm foolish enough to
>> believe that a script is always a linear affair, like driving
>> a car past scenery.

Don't think of a *coding* script as a linear affair... think of the
*execution* of the script as linear. If your code is executing in the main
routine, then calls subroutine-1, which calls subroutine-2, then that's
the "linearity" that is relevant... and which is what makes localized
variables so valuable.

Hope this helps...jon




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Jon Seidel, CMC                   +1-510-530-6314
EDP Consulting, Inc.                www.edpci.com

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