exit main( @ARGV );
{
    my $sub;
    BEGIN {
        $sub= sub {
            # ...
        };
    }
    sub GlobalRoutine {
        &$sub( ... );
    }
}
sub main {
    # ...
}

[download]

It is easy to put this in places where the BEGIN block becomes necessary. Some are much more subtle than this. Without the BEGIN block, $sub is declared and GlobalRoutine is compiled before $sub is initialized so it then becomes possible for GlobalRoutine to be called while $sub is still undef.

I'm sorry that Perl doesn't have real static variables such that I have to resort to an extra empty block and doing the initialization in a BEGIN block. Note that this trick won't work if you are using mod_perl.

FYI, since I didn't use any local variables in the anonymous subroutine, it isn't a closure in my book.

        - tye (but my friends call me "Tye")

In reply to (tye)Re2: Functions by tye
in thread Functions by fgcr

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