If you use closures, you can force a different internal state for each range operator, e.g.:

sub mkrange {
  my ($r1, $r2) = @_;
  return sub { /$r1/../$r2/ };
}

my $range1 = mkrange(qr/FIRST/, qr/SECOND/);
my $range2 = mkrange(qr/THIRD/, qr/FOURTH/);

while (<DATA>) {
  if ( $range1->() ) {
    print "R1: $_";
  }
  if ( $range2->() ) {
    print "R2: $_";
  }
}
__END__
junk
FIRST
1
2
3
SECOND
junk
THIRD
4
5
6
FOURTH
junk
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