in reply to Re: Is your module clobbering predefined variables?
in thread Is your module clobbering predefined variables?

You mean, you've never used 
    while (<>) { ... }

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Because that's the most common construct that sets $_ without localizing it.

Abigail

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Re: Re: Is your module clobbering predefined variables?
by IlyaM (Parson) on Apr 14, 2003 at 12:16 UTC
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      Shouldn't it be in the language - that the $_ variable is by default localized to module? It's hardly usefull to maintain the topic across multiple modules. Anybody knows how it is to be in Perl 6?
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[d/l]
        No, that would be very, very bad. That would disable you to write functions "the Perl" way, that is, when given no arguments, they act on $_.

        Besides, from the language aspect, there is no such thing as a "module scope".

        Abigail

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[d/l]
        It's discussed in Apocalypse 6, though lore had it that $_ would indeed be lexically scoped to each sub.

        Furthermore, a method will see $_ as "this" upon entry, so it will almost never work the old way (sorry, Abigail-II).

        Page 9 shows "Your caller's current topic is named $CALLER::_." and goes on to illustrate how to use it as a default parameter, so if you call it without an argument the function uses the caller's $_. But the function can call it by whatever formal name it likes for that parameter.

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