def chars.ok
import ezx@1.11.0.0/src/add/plan.bend as Planimport Base
515def chars.ok(text: String) -> Bool:
516 match text:
517 case SNil{}:
518 True{}
519 case SCon{+h, t}:
520 +rest = chars.ok(t)
521 Bool.and(char.ok(h), rest)