You should use an enum type as value in your HashMap
. That enum needs to have a variant for each possible type (boolean, number, string, list, map…) and an associated value of appropriate type for each variant:
enum JsonValue<'a> {
String(&'a str),
VecOfString(Vec<String>),
AnotherHashMap(HashMap<&'a str, u32>),
}
Fortunately, there already is an implementation of a JSON value type, part of the serde_json crate which is built on the serde crate.
Here is how your code would look if you used the serde_json crate:
extern crate serde_json;
use serde_json::{Value, Map, Number};
fn main() {
let mut inner_map = Map::new();
inner_map.insert("x".to_string(), Value::Number(Number::from(10u64)));
inner_map.insert("y".to_string(), Value::Number(Number::from(20u64)));
let mut map = Map::new();
map.insert("key1".to_string(), Value::String("test".to_string()));
map.insert(
"key2".to_string(),
Value::Array(vec![
Value::String("a".to_string()),
Value::String("b".to_string()),
]),
);
map.insert("key3".to_string(), Value::Object(inner_map));
println!("{}", serde_json::to_string(&map).unwrap());
// => {"key1":"test","key2":["a","b"],"key3":{"x":10,"y":20}}
}