serde_json_lodash/array/
initial.rs

1use crate::lib::{json, Value};
2
3/// See lodash [initial](https://lodash.com/docs/#initial)
4pub fn initial(v: Value) -> Value {
5    match v {
6        Value::Null => json!([]),
7        Value::Bool(_) => json!([]),
8        Value::String(s) => {
9            let mut vec = s.chars().map(|x| json!(x)).collect::<Vec<Value>>();
10            if vec.len() <= 1 {
11                return json!([]);
12            }
13            vec.pop();
14            Value::Array(vec)
15        }
16        Value::Number(_) => json!([]),
17        Value::Array(mut vec) => {
18            if vec.len() <= 1 {
19                return json!([]);
20            }
21            vec.pop();
22            Value::Array(vec)
23        }
24        Value::Object(_) => json!([]),
25    }
26}
27
28/// Based on [initial()]
29///
30/// Examples:
31///
32/// ```rust
33/// #[macro_use] extern crate serde_json_lodash;
34/// use serde_json::json;
35/// assert_eq!(
36///   initial!(json!([1, 2, 3])),
37///   json!([1, 2])
38/// );
39/// ```
40///
41/// More examples:
42///
43/// ```rust
44/// # #[macro_use] extern crate serde_json_lodash;
45/// # use serde_json::json;
46/// assert_eq!(initial!(), json!([]));
47/// assert_eq!(initial!(json!(null)), json!([]));
48/// assert_eq!(initial!(json!(false)), json!([]));
49/// assert_eq!(initial!(json!(0)), json!([]));
50/// assert_eq!(initial!(json!("")), json!([]));
51/// assert_eq!(initial!(json!("abc")), json!(["a","b"]));
52/// assert_eq!(initial!(json!("日本国")), json!(["日","本"]));
53/// assert_eq!(initial!(json!({})), json!([]));
54/// assert_eq!(initial!(json!({"a":1})), json!([]));
55/// ```
56#[macro_export]
57macro_rules! initial {
58    () => {
59        json!([])
60    };
61    ($a:expr $(,)*) => {
62        $crate::initial($a)
63    };
64    ($a:expr, $($rest:tt)*) => {
65        $crate::initial($a)
66    };
67}
serde_json_lodash/array/initial.rs

serde_json_lodash/array/
initial.rs
