Macro serde_json_lodash::head

macro_rules! head {
    () => { ... };
    ($a:expr $(,)*) => { ... };
    ($a:expr, $($rest:tt)*) => { ... };
}

Description can be found in lodash head

Examples:

#[macro_use] extern crate serde_json_lodash;
use serde_json::json;
assert_eq!(
  head!(json!([1, 2, 3])),
  json!(1)
);
assert_eq!(
  head!(json!([])),
  json!(null)
);

More examples:

assert_eq!(head!(), json!(null));
assert_eq!(head!(json!(null)), json!(null));
assert_eq!(head!(json!(false)), json!(null));
assert_eq!(head!(json!(0)), json!(null));
assert_eq!(head!(json!("")), json!(null));
assert_eq!(head!(json!("ab")), json!("a"));
assert_eq!(head!(json!("日本")), json!("日"));
assert_eq!(head!(json!({})), json!(null));
assert_eq!(head!(json!({"a":1})), json!(null));