use serde_json::{self, Value}; // 1.0.38

fn main() {
    let all_type = b"
    {
       \"number\": 123,
       \"string\": \"abcdefg\",
       \"boolean\": true
    }";
    let string_only = b"
    {
       \"string1\": \"abcdefg\",
       \"string2\": \"abcdefg\",
       \"string3\": \"abcdefg\",
       \"string_array\": [\"abcd\", \"efg\"]
    }";

    let all: Value = serde_json::from_slice(all_type).unwrap();
    let string: Value = serde_json::from_slice(string_only).unwrap();
    let flag1 = is_data_valid(&all);
    let flag2 = is_data_valid(&string);
    println!("{}", flag1);
    println!("{}", flag2);
}

fn is_data_valid(val: &serde_json::Value) -> bool {
    match val.as_object() {
        Some(map) => {
            for key in map.keys() {
                if !is_data_valid(&map[key]) {
                    return false;
                }
            }
            true
        },
        None => {
            match val.as_array() {
                Some(array) => {
                    for obj in array {
                        if !is_data_valid(&obj) {
                            return false;
                        }
                    }
                    true
                },
                None => val.is_string()
            }
        },
    }
}