def chars.ok
import ezx@1.11.0.0/src/remove/plan.bend as Planimport Base
80# whether every char of a text may
81def chars.ok(text: String) -> Bool:
82 match text:
83 case SNil{}:
84 True{}
85 case SCon{+h, t}:
86 +rest = chars.ok(t)
87 Bool.and(char.ok(h), rest)