val .select = impure fn(.entries) {
    if .entries is not list: throw "invalid args"
    if len(.entries) == 0: return ""

    # print the menu
    writeln join "\n", map(fn(.e, .i) $"\.i:2;: \.e;", .entries, 1..len .entries)

    val .idx = number read(
        "Select entry #: ",
        fn(.x) {
            if not .x -> RE/^[0-9]+$/: return false
            val .y = number .x
            .y > 0 and .y <= len(.entries)
        },
        "invalid selection\n", -1,
    )

    .entries[.idx]
}

writeln .select(["fee fie", "eat pi", "huff and puff", "tick tock"])