$mid = int( ( $lo + $hi ) / 2 );
    if ( $hi == $lo ) { return $mid }

##</code><code>##

    return $hi
        if  $hi == $lo;
    $mid = int( ( $lo + $hi ) / 2 );

##</code><code>##

    if ( $suff[ $indices[ $index ] ] =~ /^$pattern/ ) {
        push @positions, $indices[ $index ] + 1;
    }
    else {
        last;
    }

##</code><code>##

    last
        if  $suff[ $indices[ $index ] ] !~ /^$pattern/;
    push @positions, $indices[ $index ] + 1;