byten 0.0.13

A binary codec library for efficient encoding and decoding of data structures
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
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186

/// Codec for the unit type `()`.
/// The unit codec encodes and decodes the unit type without consuming any bytes.
///
/// # Examples
/// ```rust
/// use byten::{UnitCodec, Decoder, Encoder, Measurer, FixedMeasurer};
///
/// let codec = UnitCodec::new();
///
/// let mut encoded = [0u8; 0];
/// let mut offset = 0;
/// codec.encode(&(), &mut encoded, &mut offset).unwrap();
/// assert_eq!(offset, 0);
///
/// let mut decode_offset = 0;
/// let decoded: () = codec.decode(&encoded, &mut decode_offset).unwrap();
/// assert_eq!(decoded, ());
/// assert_eq!(decode_offset, 0);
///
/// let size = codec.measure(&()).unwrap();
/// assert_eq!(size, 0);
///
/// let fixed_size = codec.measure_fixed();
/// assert_eq!(fixed_size, 0);
/// ```
pub struct UnitCodec;

impl UnitCodec {
    pub const fn new() -> Self {
        Self
    }
}

impl crate::Decoder<'_, '_> for UnitCodec {
    type Decoded = ();

    fn decode(
        &self,
        _encoded: &'_ [u8],
        _offset: &mut usize,
    ) -> Result<Self::Decoded, crate::error::DecodeError> {
        Ok(())
    }
}

impl crate::Encoder for UnitCodec {
    type Decoded = ();

    fn encode(
        &self,
        _decoded: &Self::Decoded,
        _encoded: &mut [u8],
        _offset: &mut usize,
    ) -> Result<(), crate::error::EncodeError> {
        Ok(())
    }
}

impl crate::Measurer for UnitCodec {
    type Decoded = ();

    fn measure(&self, _decoded: &Self::Decoded) -> Result<usize, crate::error::EncodeError> {
        Ok(0)
    }
}

impl crate::FixedMeasurer for UnitCodec {
    fn measure_fixed(&self) -> usize {
        0
    }
}

macro_rules! tuple_codecs {
    ($name:ident, ($($idx:tt),*), ($($codec:ident),*), ($($codec_var:ident),*), ($($item:ident),*)) => {
        pub struct $name<$($codec),*>($(pub $codec),*);

        impl <$($codec),*> $name<$($codec),*> {
            pub const fn new($($codec_var: $codec),*) -> Self {
                Self( $($codec_var),* )
            }
        }

        impl<'encoded, 'decoded, $($codec),*> crate::Decoder<'encoded, 'decoded> for $name<$($codec),*>
        where
            $($codec: crate::Decoder<'encoded, 'decoded>,)*
        {
            type Decoded = ($($codec::Decoded),*,);

            fn decode(
                &self,
                encoded: &'encoded [u8],
                offset: &mut usize,
            ) -> Result<Self::Decoded, crate::error::DecodeError> {
                let decoded = ( $( self.$idx.decode(encoded, offset)? ),* , );
                Ok(decoded)
            }
        }

        impl<$($codec),*, $($item: Sized),*> crate::Encoder for $name<$($codec),*>
        where
            $(
                $codec: crate::Encoder<Decoded = $item>,
            )*
        {
            type Decoded = ($($item),*,);

            fn encode(
                &self,
                decoded: &Self::Decoded,
                encoded: &mut [u8],
                offset: &mut usize,
            ) -> Result<(), crate::error::EncodeError> {
                $( self.$idx.encode(&decoded.$idx, encoded, offset)?; )*
                Ok(())
            }
        }

        impl<$($codec),*, $($item: Sized),*> crate::Measurer for $name<$($codec),*>
        where
            $($codec: crate::Measurer<Decoded = $item>,)*
        {
            type Decoded = ($($item),*,);

            fn measure(&self, decoded: &Self::Decoded) -> Result<usize, crate::error::EncodeError> {
                let mut size: usize = 0;
                $( size += self.$idx.measure(&decoded.$idx)?; )*
                Ok(size)
            }
        }

        impl<'decoded, $($codec),*, $($item: 'decoded + Sized),*> crate::FixedMeasurer for $name<$($codec),*>
        where
            $($codec: crate::FixedMeasurer<Decoded = &'decoded $item>,)*
        {
            fn measure_fixed(&self) -> usize {
                0usize $( + self.$idx.measure_fixed() )*
            }
        }
    };
}

pub type Tuple0Codec = UnitCodec;

tuple_codecs!(Tuple1Codec, (0), (Codec1), (codec1), (Item1));
tuple_codecs!(
    Tuple2Codec,
    (0, 1),
    (Codec1, Codec2),
    (codec1, codec2),
    (Item1, Item2)
);
tuple_codecs!(
    Tuple3Codec,
    (0, 1, 2),
    (Codec1, Codec2, Codec3),
    (codec1, codec2, codec3),
    (Item1, Item2, Item3)
);
tuple_codecs!(
    Tuple4Codec,
    (0, 1, 2, 3),
    (Codec1, Codec2, Codec3, Codec4),
    (codec1, codec2, codec3, codec4),
    (Item1, Item2, Item3, Item4)
);
tuple_codecs!(
    Tuple5Codec,
    (0, 1, 2, 3, 4),
    (Codec1, Codec2, Codec3, Codec4, Codec5),
    (codec1, codec2, codec3, codec4, codec5),
    (Item1, Item2, Item3, Item4, Item5)
);
tuple_codecs!(
    Tuple6Codec,
    (0, 1, 2, 3, 4, 5),
    (Codec1, Codec2, Codec3, Codec4, Codec5, Codec6),
    (codec1, codec2, codec3, codec4, codec5, codec6),
    (Item1, Item2, Item3, Item4, Item5, Item6)
);
tuple_codecs!(
    Tuple7Codec,
    (0, 1, 2, 3, 4, 5, 6),
    (Codec1, Codec2, Codec3, Codec4, Codec5, Codec6, Codec7),
    (codec1, codec2, codec3, codec4, codec5, codec6, codec7),
    (Item1, Item2, Item3, Item4, Item5, Item6, Item7)
);