def trie.at
import bend-kit-regex@0.8.0.0/regex.bend as Regeximport Base
715# The value at key k, stored as n = k + 1.
716def trie.at(-V: Data, t: Trie<V>, +k: U32) -> Maybe<&2, V>:
717 +n = (k + 1 : U32)
718 trie.get(V, t, U32.is_eq(n, 1), U32.is_even(n), n)