def allowed.ok

shake@0.7.0.0 · src/cli.bend:420

import Base

420# whether `v` is listed; the empty list answers no
421def allowed.ok(cs: List<&2, String>, +vv: String) -> Bool:
422  match cs:
423    case Nil{}:
424      False{}
425    case Con{+h, t}:
426      allowed.ok.at(String.eq(h, vv), allowed.ok(t, vv))