Hello fellow monks.

The code below uses a source code filter, which replaces all "word"s with "worlds". However, it only prints "Hello word" instead of "Hello world".

# test code
my $a = 
'use filtertest;
BEGIN { print "eval test\n"; }
sub {
    print "Hello word\n";
}->();
END { print "eval over\n" }';
eval $a;
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# module: filtertest
package filtertest;
use Filter::Util::Call;
sub import {
    my($type, @arguments) = @_;
    filter_add(
        sub {
            my($status);
            $status = filter_read();
            s/word/world/g if ($status > 0);
            $status
        } 
    )
}
1;
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The problem is that I use eval to evaluate the code string. Actually, perl -e 'use filtertest; print "Hello word\n"' gives the same, i.e. wrong, result. But

use filtertest; 
print "Hello word\n";
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works properly.

It seems the BEGIN magic of the filter is not executed when being 'eval'ed. Does this mean that Filter::Util::Call confilcts with the builtin eval function?

Thanks in advance. Feel free to correct my mistakes.