# See the License for the specific language governing permissions and
# limitations under the License.
-var rp: String = new RopeString.from("xxx")
-rp += "yyy"
+import core
+intrude import core::text::ropes
+
+var rp: String = new Concat("xxx", "yyy")
rp += "zzz"
var arr = ["FlatString", rp]
print arr.to_s