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#![cfg(feature = "alloc")]
//#![feature(trace_macros)]
#[macro_use]
extern crate nom;
use nom::{character::is_alphanumeric, number::complete::recognize_float};
use std::str;
use std::collections::HashMap;
#[derive(Debug, PartialEq)]
pub enum JsonValue {
Str(String),
Num(f32),
Array(Vec<JsonValue>),
Object(HashMap<String, JsonValue>),
}
named!(float<f32>, flat_map!(recognize_float, parse_to!(f32)));
//FIXME: verify how json strings are formatted
named!(
string<&str>,
delimited!(
char!('"'),
//map_res!(escaped!(call!(alphanumeric), '\\', is_a!("\"n\\")), str::from_utf8),
map_res!(
escaped!(take_while1!(is_alphanumeric), '\\', one_of!("\"n\\")),
str::from_utf8
),
char!('"')
)
);
named!(
array<Vec<JsonValue>>,
ws!(delimited!(
char!('['),
separated_list!(char!(','), value),
char!(']')
))
);
named!(
key_value<(&str, JsonValue)>,
ws!(separated_pair!(string, char!(':'), value))
);
named!(
hash<HashMap<String, JsonValue>>,
ws!(map!(
delimited!(char!('{'), separated_list!(char!(','), key_value), char!('}')),
|tuple_vec| {
let mut h: HashMap<String, JsonValue> = HashMap::new();
for (k, v) in tuple_vec {
h.insert(String::from(k), v);
}
h
}
))
);
named!(
value<JsonValue>,
ws!(alt!(
hash => { |h| JsonValue::Object(h) } |
array => { |v| JsonValue::Array(v) } |
string => { |s| JsonValue::Str(String::from(s)) } |
float => { |num| JsonValue::Num(num) }
))
);
#[test]
fn json_object() {
let input =
r#"{
"a": 42,
"b": "x"
}\0"#;
let mut expected_map = HashMap::new();
expected_map.insert(String::from("a"), JsonValue::Num(42f32));
expected_map.insert(String::from("b"), JsonValue::Str(String::from("x")));
let expected = JsonValue::Object(expected_map);
assert_eq!(expected, value(input.as_bytes()).unwrap().1);
}
#[test]
fn json_array() {
let input =
r#"[
42,
"x"
]\0"#;
let expected_vec = vec![
JsonValue::Num(42f32),
JsonValue::Str(String::from("x"))
];
let expected = JsonValue::Array(expected_vec);
assert_eq!(expected, value(input.as_bytes()).unwrap().1);
}
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