return/exit/die after else. YUCK!

gistfile1.txt

IO.pm

sub MAKE-ABSOLUTE-PATH($path,$abspath) {
    if $path.ord == 47 {              # 4x faster substr($path,0,1) eq "/"
        return $path;
    }
    elsif substr($path,1,1) eq ':' {  # assume C: something
        if substr($path,2,1) eq "/" { #  assume C:/ like prefix
            return $path;
        }
        elsif substr($abspath,0,2) ne substr($path,0,2) {
            die "Can not set relative dir from different roots";
        }
        else {
            return $abspath ~ substr($path,2);
        }
    }
    else {                            # assume relative path
        return $abspath ~ $path;
    }
}

=>

sub MAKE-ABSOLUTE-PATH($path,$abspath) {
    $path.ord == 47 and              # 4x faster substr($path,0,1) eq "/"
        return $path;

    substr($path,1,1) ne ':' and     # C: like prefix?
        return $abspath ~ $path;     # assume relative path

    # assume C: something
    substr($path,2,1) eq "/" and     #  assume C:/ like prefix
        return $path;

    substr($abspath,0,2) ne substr($path,0,2) and
        die "Can not set relative dir from different roots";
    return $abspath ~ substr($path,2);
}