def String.split

Base · base.bend:2210

2210def String.split(s: String, +sep: Char) -> List<&2, String>:
2211  match s:
2212    case SNil{}:
2213      [SNil{}]
2214    case SCon{+h, t}:
2215      String.split.fin(h, String.split(t, sep), Char.is_eq(h, sep))