messagepack-core 0.2.4

messagepack for `no_std`
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
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93

//! Nil and `Option` decoding helpers.

use super::{Decode, DecodeBorrowed, Error};
use crate::{formats::Format, io::IoRead};

/// Decode the MessagePack `nil` value.
pub struct NilDecoder;

impl<'de> DecodeBorrowed<'de> for NilDecoder {
    type Value = ();

    fn decode_borrowed_with_format<R>(
        format: Format,
        _reader: &mut R,
    ) -> core::result::Result<Self::Value, Error<R::Error>>
    where
        R: IoRead<'de>,
    {
        match format {
            Format::Nil => Ok(()),
            _ => Err(Error::UnexpectedFormat),
        }
    }
}

impl<'de> DecodeBorrowed<'de> for () {
    type Value = ();

    fn decode_borrowed_with_format<R>(
        format: Format,
        reader: &mut R,
    ) -> core::result::Result<Self::Value, Error<R::Error>>
    where
        R: IoRead<'de>,
    {
        NilDecoder::decode_borrowed_with_format(format, reader)
    }
}

impl<'de, V> Decode<'de> for Option<V>
where
    V: Decode<'de>,
{
    type Value<'a>
        = Option<V::Value<'a>>
    where
        Self: 'a,
        'de: 'a;
    fn decode_with_format<'a, R>(
        format: Format,
        reader: &'a mut R,
    ) -> Result<Self::Value<'a>, Error<R::Error>>
    where
        R: IoRead<'de>,
        'de: 'a,
    {
        match format {
            Format::Nil => Ok(None),
            other => {
                let val = V::decode_with_format(other, reader)?;
                Ok(Some(val))
            }
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn decode_nil() {
        let buf: &[u8] = &[0xc0];
        let mut r = crate::io::SliceReader::new(buf);
        NilDecoder::decode(&mut r).unwrap();
        assert_eq!(r.rest().len(), 0);
    }

    #[test]
    fn decode_option() {
        let buf: &[u8] = &[0xc0];
        let mut r = crate::io::SliceReader::new(buf);
        let decoded = Option::<bool>::decode(&mut r).unwrap();
        assert_eq!(decoded, None);
        assert_eq!(r.rest().len(), 0);

        let buf: &[u8] = &[0xc3];
        let mut r = crate::io::SliceReader::new(buf);
        let decoded = Option::<bool>::decode(&mut r).unwrap();
        assert_eq!(decoded, Some(true));
        assert_eq!(r.rest().len(), 0);
    }
}