jutils 0.1.2

JSON Utilities for Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56

pub trait JsonExtender {
    fn extend_json_str(&mut self, s: &str);
    fn extend_json_str_fragment(&mut self, s: &str);
}

static HEX: &[u8; 16] = br#"0123456789abcdef"#;

fn extend_hex_16(buf: &mut Vec<u8>, x: u16) {
    buf.push(HEX[(x>>12&0xF) as usize]);
    buf.push(HEX[(x>>8&0xF) as usize]);
    buf.push(HEX[(x>>4&0xF) as usize]);
    buf.push(HEX[(x>>0&0xF) as usize]);
}

impl JsonExtender for Vec<u8> {
    /// Convert provide string into a valid JSON String and append it to the 
    /// provided Vec<u8>.
    fn extend_json_str(&mut self, s: &str) {
        self.push(b'"');
        self.extend_json_str_fragment(s);
        self.push(b'"');
    }
    /// Convert provide string into a valid JSON String fragment and append it
    /// to the provided Vec<u8>. 
    /// 
    /// A converted JSON String fragment will not included the wrapped
    /// quotation characters.
    fn extend_json_str_fragment(&mut self, s: &str) {
        let mut tmp = [0u8; 10];
        for c in s.chars() {
            if c < ' ' {
                self.push(b'\\');
                match c {
                    '\n'=> self.push(b'n'),
                    '\r' => self.push(b'r'),
                    '\t'=> self.push(b'r'),
                    _ => {
                        self.push(b'u');
                        extend_hex_16(self, c as u16);
                    }
                }
            } else if c == '>' || c == '<' || c == '&' {
                self.push(b'\\');
                self.push(b'u');
                extend_hex_16(self, c as u16);
            } else if c == '\\' {
                self.push(b'\\');
                self.push(b'\\');
            } else if c == '"' {
                self.push(b'"');
            } else {
                self.extend(c.encode_utf8(&mut tmp).as_bytes());
            }
        }
    }
}