bitrange 0.3.0

Simple plugin to map bits in integer values to fields
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

#![deny(warnings)]
#![cfg_attr(not(feature = "std"), no_std)]

#[cfg(feature = "panic")]
mod error {
    #[cfg(not(feature = "std"))]
    use core::fmt::Binary;
    #[cfg(not(feature = "std"))]
    use core::marker::PhantomData;
    #[cfg(feature = "std")]
    use std::fmt::Binary;
    #[cfg(feature = "std")]
    use std::marker::PhantomData;

    #[derive(Debug)]
    pub struct Error<T> {
        _phantomdata: PhantomData<T>,
    }

    impl<T> Error<T>
    where
        T: Binary,
    {
        pub fn invalid_bits(expected: T, provided: T) -> Error<T> {
            panic!(
                "Invalid bits, expected 0b{:0b}, got 0b{:0b}",
                expected, provided
            );
        }
    }
}

#[cfg(not(feature = "panic"))]
mod error {
    #[derive(Debug)]
    pub struct Error<T> {
        pub expected: T,
        pub provided: T,
    }

    impl<T> Error<T> {
        pub fn invalid_bits(expected: T, provided: T) -> Error<T> {
            Error { expected, provided }
        }
    }
}

pub use error::Error;

/// Create a bitrange struct.
///
/// ```rust
/// #![deny(warnings)]
/// #[macro_use]
/// extern crate bitrange;
/// #[macro_use]
/// extern crate bitrange_plugin;
/// # fn main() {
/// bitrange! {
///     Test: u8, "u8",         // the name of the struct and the size of the internal integer
///     "aaa1_0bbb",            // the format of the bits in the internal integer
///     a: first,               // map the bits that are marked as `a` to field `first`
///     b: second set_second    // map the bits that are marked as `b` to field `second`
///                             // and create a setter `set_second` that sets a given value to `b`
/// }
/// # }
/// ```
#[macro_export]
macro_rules! bitrange {
    (
        $struct_name:ident:
        $struct_size:ty,
        $struct_size_string:tt,
        $format:tt,
        $(
            $field_format:ident:
            $(
                $field_name:ident
            )+
        ),+
    ) => {
        #[derive(Bitrange)]
        #[BitrangeMask = $format]
        #[BitrangeSize = $struct_size_string]
        pub struct $struct_name {
            #[allow(dead_code)]
            bits: $struct_size
        }
        impl Default for $struct_name {
            #[allow(dead_code)]
            fn default() -> $struct_name {
                #[allow(dead_code, non_snake_case)]
                let DEFAULT_VALUE: $struct_size = $struct_name::__bitrange_get_default_value();
                $struct_name {
                    bits: DEFAULT_VALUE
                }
            }
        }
        impl $struct_name {
            #[allow(dead_code)]
            pub fn from(bits: $struct_size) -> Result<$struct_name, ::bitrange::Error<$struct_size>> {
                #[allow(dead_code, non_snake_case)]
                let DEFAULT_VALUE: $struct_size = $struct_name::__bitrange_get_default_value();
                #[allow(dead_code, non_snake_case)]
                let DEFAULT_MASK: $struct_size = $struct_name::__bitrange_get_default_mask();

                if bits & DEFAULT_MASK == DEFAULT_VALUE {
                    Ok($struct_name {
                        bits
                    })
                } else {
                    Err(::bitrange::Error::invalid_bits(DEFAULT_VALUE, bits & DEFAULT_MASK))
                }
            }
        }
        $(
            bitrange_impl_field!(
                $struct_name,
                $struct_size,
                $format,
                $field_format,
                $($field_name),+
            );
        )+
    }
}

#[doc(hidden)]
#[macro_export]
macro_rules! bitrange_impl_field {
    ($struct_name:ident, $struct_size:tt, $format:tt, $field_format:ident, $field_get:ident) => {
        impl $struct_name {
            pub fn $field_get(&self) -> $struct_size {
                #[allow(dead_code, non_snake_case)]
                let MASK: $struct_size =
                    $struct_name::__bitrange_get_mask(stringify!($field_format));
                #[allow(dead_code, non_snake_case)]
                let OFFSET: usize = $struct_name::__bitrange_get_offset(stringify!($field_format));

                (self.bits & MASK) >> OFFSET
            }
        }
    };
    (
        $struct_name:ident,
        $struct_size:tt,
        $format:tt,
        $field_format:ident,
        $field_get:ident,
        $field_set:ident
    ) => {
        bitrange_impl_field!(
            $struct_name,
            $struct_size,
            $format,
            $field_format,
            $field_get
        );

        impl $struct_name {
            pub fn $field_set(&mut self, value: $struct_size) -> &mut Self {
                #[allow(dead_code, non_snake_case)]
                let MASK: $struct_size =
                    $struct_name::__bitrange_get_mask(stringify!($field_format));
                #[allow(dead_code, non_snake_case)]
                let OFFSET: usize = $struct_name::__bitrange_get_offset(stringify!($field_format));
                self.bits &= !MASK;
                self.bits |= (value << OFFSET) & MASK;
                self
            }
        }
    };
}