pub fn parse(input: &str) -> Result<Json, String>Expand description
Parse JSON text.
ยงErrors
Returns a description if the input is not valid JSON, exceeds 16 MiB, or contains more than 256 nested arrays and objects.
Examples found in repository?
examples/parse_and_build.rs (line 17)
14fn main() {
15 let request = r#"{"jsonrpc":"2.0","id":7,"method":"initialize","params":{"trace":"off"}}"#;
16
17 let value = parse(request).expect("the request is valid JSON");
18
19 // `get` walks objects; it returns `None` for a missing key and for
20 // a value that is not an object, so chains do not need a type check
21 // at every step.
22 assert_eq!(
23 value.get("method").and_then(Json::as_str),
24 Some("initialize")
25 );
26 assert_eq!(
27 value
28 .get("params")
29 .and_then(|p| p.get("trace"))
30 .and_then(Json::as_str),
31 Some("off")
32 );
33
34 // Building a reply. Object keys come back out in sorted order,
35 // which makes serialised output comparable in a test without
36 // parsing it again.
37 let reply = Json::object(vec![
38 ("jsonrpc", Json::str("2.0")),
39 ("id", value.get("id").cloned().unwrap_or(Json::Null)),
40 (
41 "result",
42 Json::object(vec![("capabilities", Json::object(vec![]))]),
43 ),
44 ]);
45
46 println!("{}", reply.to_json());
47
48 // Malformed input is an error with a message, not a panic and not
49 // a silent default.
50 let bad = parse("{\"unterminated\": ");
51 println!("malformed input: {}", bad.unwrap_err());
52}