/*
 *  call-seq:
 *     index_reader.norms(field) -> string
 *  
 *  Expert: Returns a string containing the norm values for a field. The
 *  string length will be equal to the number of documents in the index and it
 *  could have null bytes.
 */
static VALUE
frt_ir_norms(VALUE self, VALUE rfield)
{
    IndexReader *ir = (IndexReader *)DATA_PTR(self);
    uchar *norms;
    norms = ir_get_norms(ir, frt_field(rfield));
    if (norms) {
        return rb_str_new((char *)norms, ir->max_doc(ir));
    } else {
        return Qnil;
    }
}