def String.concat
import Base2174def String.concat(xs: List<&2, String>) -> String:
2175 match xs:
2176 case Nil{}:
2177 SNil{}
2178 case h <> t:
2179 String.append(h, String.concat(t))
import Base2174def String.concat(xs: List<&2, String>) -> String:
2175 match xs:
2176 case Nil{}:
2177 SNil{}
2178 case h <> t:
2179 String.append(h, String.concat(t))