monkeying around in grain

t.gr

import { Set, size, fromList } from "set"
import { length } from "string"

enum Value {
  NumberValue(Number),
  StringValue(String),
  SetValue(Set<Value>),
}

let length = (x) => {
  match(x) {
    SetValue(s) => size(s),
    StringValue(s) => length(s),
    _ => fail "number",
  }
}

let a = StringValue("foo")
print(length(a))

let c = SetValue(fromList([StringValue("foo"), NumberValue(11)]))
print(length(c))

let b = NumberValue(111)
print(length(b))