Struct Scheme

pub struct Scheme(/* private fields */);

Defines a pattern giving meaning to different regions of a bit string.

Implementations

impl Scheme

pub fn new<I: IntoIterator<Item = Field>>(pattern: I) -> Self

Example

let unsigned_3 = Field::unsigned(3);

let scheme = Scheme::new([
    Field::signed(5),
    Field::BIT,
    unsigned_3,
    unsigned_3,
    Field::UNSIGNED_4,
    Field::aligned(23, 1, true),
    Field::unsigned(32),
    Field::signed(32),
    Field::bytes(4, false),
    Field::aligned(6, 8, true)
]);

let time_since_epoch = Field::UNSIGNED_64;
let identifier = Field::UNSIGNED_8;
let datatype = Field::UNSIGNED_4;
let data = Field::BYTES;

let scheme2 = Scheme::new([time_since_epoch, identifier, datatype, data]);

pub fn len(&self) -> isize

Number of bits extracted

If any field in the scheme has a negative length, this method returns -1, indicating the scheme extracts a variable number of bits.

Example

let unsigned_3 = Field::unsigned(3);

let scheme = Scheme::new([
    Field::signed(5), Field::BIT, unsigned_3, unsigned_3, Field::UNSIGNED_4
]);

assert_eq!(scheme.len(), 16);

let scheme2 = Scheme::new([
    Field::aligned(23, 1, true),
    Field::unsigned(0),
    Field::unsigned(32),
    Field::bytes(4, false),
    Field::aligned(0, 8, false),
    Field::aligned(7, 8, true)
]);

let scheme3 = Scheme::new([
    Field::aligned(23, 1, true),
    Field::unsigned(0),
    Field::unsigned(32),
    Field::signed(-1),
    Field::bytes(4, false),
    Field::aligned(0, 8, false),
    Field::aligned(7, 8, true)
]);

assert_eq!(scheme3.len(), -1);

pub fn split_bits(&self, bits: &Bits) -> Vec<Bits>

Extracts the data associated with the fields of this scheme

Example

let unsigned_3 = Field::unsigned(3);

let scheme = Scheme::new([
    Field::signed(5), Field::BIT, unsigned_3, unsigned_3, Field::UNSIGNED_4
]);

let bits = Bits::new([0xBA, 0x1C]);
let parts = scheme.split_bits(&bits);

assert_eq!(bits_as::int8(&parts[0]), -6);
assert_eq!(bits_as::uint8(&parts[1]), 1);
assert_eq!(bits_as::uint8(&parts[2]), 2);
assert_eq!(bits_as::uint8(&parts[3]), 6);
assert_eq!(bits_as::uint8(&parts[4]), 1);

let bits2 = Bits::new([0xBA]);
let parts2 = scheme.split_bits(&bits2);

assert_eq!(bits_as::int8(&parts2[0]), -6);
assert_eq!(bits_as::uint8(&parts2[1]), 1);
assert_eq!(bits_as::uint8(&parts2[2]), 2);
assert_eq!(bits_as::uint8(&parts2[3]), 0);
assert_eq!(bits_as::uint8(&parts2[4]), 0);

let scheme2 = Scheme::new([
    Field::aligned(23, -1, true),
    Field::aligned(0, -1, false),
    Field::bytes(-1, false),
    Field::signed(-1),
    Field::unsigned(-1),
    Field::unsigned(0),
    Field::unsigned(32),
    Field::bytes(4, false),
    Field::aligned(0, 8, false),
    Field::aligned(7, 8, true),
    Field::signed(-1),
    Field::unsigned(-1)
]);

let bytes = [0xBA, 0xDC, 0xFE, 0x10, 0x32];
let bits3 = Bits::from(bytes.as_slice()); // 38-bits
let parts = scheme2.split_bits(&bits3);

assert_eq!(bits_as::int32(&parts[0]), 0xFFFEDCBAu32 as i32);
assert_eq!(parts[1], Bits::empty());
assert_eq!(bits_as::vec_u8(&parts[2]), vec![0x21]);
assert_eq!(bits_as::vec_i32(&parts[3]), vec![-28]);
assert_eq!(parts[4], Bits::empty());
assert_eq!(parts[5], Bits::empty());
assert_eq!(parts[6], Bits::zeros(32));
assert_eq!(parts[7], Bits::zeros(32));
assert_eq!(parts[8], Bits::empty());
assert_eq!(parts[9], Bits::zeros(56));
assert_eq!(parts[10], Bits::empty());
assert_eq!(parts[11], Bits::empty());

pub fn split_bits_at(&self, index: usize, bits: &Bits) -> Vec<Bits>

Extracts the data associated with the fields of this scheme.

Example

let unsigned_3 = Field::unsigned(3);

let scheme = Scheme::new([
    Field::signed(5), Field::BIT, unsigned_3, unsigned_3, Field::UNSIGNED_4
]);

let bits = Bits::new([0xBA, 0x1C]);
let parts = scheme.split_bits_at(0, &bits);

assert_eq!(bits_as::int8(&parts[0]), -6);
assert_eq!(bits_as::uint8(&parts[1]), 1);
assert_eq!(bits_as::uint8(&parts[2]), 2);
assert_eq!(bits_as::uint8(&parts[3]), 6);
assert_eq!(bits_as::uint8(&parts[4]), 1);

let parts2 = scheme.split_bits_at(8, &bits);

assert_eq!(bits_as::int8(&parts2[0]), -4);
assert_eq!(bits_as::uint8(&parts2[1]), 0);
assert_eq!(bits_as::uint8(&parts2[2]), 0);
assert_eq!(bits_as::uint8(&parts2[3]), 0);
assert_eq!(bits_as::uint8(&parts2[4]), 0);

let scheme2 = Scheme::new([
    Field::aligned(23, -1, true),
    Field::aligned(0, -1, false),
    Field::bytes(-1, false),
    Field::signed(-1),
    Field::unsigned(-1),
    Field::unsigned(0),
    Field::unsigned(32),
    Field::bytes(4, false),
    Field::aligned(0, 8, false),
    Field::aligned(7, 8, true),
    Field::signed(-1),
    Field::unsigned(-1)
]);

let bytes = [0xBA, 0xDC, 0xFE, 0x10, 0x32];
let bits3 = Bits::from(bytes.as_slice()); // 38-bits
let parts = scheme2.split_bits_at(4, &bits3);

assert_eq!(bits_as::int32(&parts[0]), 0x0FEDCB);
assert_eq!(parts[1], Bits::empty());
assert_eq!(bits_as::vec_u8(&parts[2]), vec![0x42]);
assert_eq!(bits_as::vec_i32(&parts[3]), vec![-2]);
assert_eq!(parts[4], Bits::empty());
assert_eq!(parts[5], Bits::empty());
assert_eq!(parts[6], Bits::zeros(32));
assert_eq!(parts[7], Bits::zeros(32));
assert_eq!(parts[8], Bits::empty());
assert_eq!(parts[9], Bits::zeros(56));
assert_eq!(parts[10], Bits::empty());
assert_eq!(parts[11], Bits::empty());

pub fn split_bytes<I: IntoIterator<Item = u8>>(&self, bytes: I) -> Vec<Bits>

Extracts the data associated with the fields of this scheme

Example

let unsigned_3 = Field::unsigned(3);

let scheme = Scheme::new([
    Field::signed(5), Field::BIT, unsigned_3, unsigned_3, Field::UNSIGNED_4
]);

let parts = scheme.split_bytes([0xBA, 0x1C]);

assert_eq!(bits_as::int8(&parts[0]), -6);
assert_eq!(bits_as::uint8(&parts[1]), 1);
assert_eq!(bits_as::uint8(&parts[2]), 2);
assert_eq!(bits_as::uint8(&parts[3]), 6);
assert_eq!(bits_as::uint8(&parts[4]), 1);

let parts2 = scheme.split_bytes([0xBA]);

assert_eq!(bits_as::int8(&parts2[0]), -6);
assert_eq!(bits_as::uint8(&parts2[1]), 1);
assert_eq!(bits_as::uint8(&parts2[2]), 2);
assert_eq!(bits_as::uint8(&parts2[3]), 0);
assert_eq!(bits_as::uint8(&parts2[4]), 0);

let scheme2 = Scheme::new([
    Field::aligned(23, -1, true),
    Field::aligned(0, -1, false),
    Field::bytes(-1, false),
    Field::signed(-1),
    Field::unsigned(-1),
    Field::unsigned(0),
    Field::unsigned(32),
    Field::bytes(4, false),
    Field::aligned(0, 8, false),
    Field::aligned(7, 8, true),
    Field::signed(-1),
    Field::unsigned(-1)
]);

let parts = scheme2.split_bytes(vec![0xBA, 0xDC, 0xFE, 0x10, 0x32]);

assert_eq!(bits_as::int32(&parts[0]), 0xFFFEDCBAu32 as i32);
assert_eq!(parts[1], Bits::empty());
assert_eq!(bits_as::vec_u8(&parts[2]), vec![0x21, 0x64]);
assert_eq!(parts[3], Bits::zeros(1));
assert_eq!(bits_as::int64(&parts[4]), 0);
assert_eq!(parts[5], Bits::empty());
assert_eq!(parts[6], Bits::zeros(32));
assert_eq!(parts[7], Bits::zeros(32));
assert_eq!(parts[8], Bits::empty());
assert_eq!(parts[9], Bits::zeros(56));
assert_eq!(parts[10], Bits::empty());
assert_eq!(parts[11], Bits::empty());

pub fn split_bytes_at<I: IntoIterator<Item = u8>>( &self, index: usize, bytes: I, ) -> Vec<Bits>

Extracts the data associated with the fields of this scheme.

Example

let unsigned_3 = Field::unsigned(3);

let scheme = Scheme::new([
    Field::signed(5), Field::BIT, unsigned_3, unsigned_3, Field::UNSIGNED_4
]);

let parts = scheme.split_bytes_at(0, [0xBA, 0x1C]);

assert_eq!(bits_as::int8(&parts[0]), -6);
assert_eq!(bits_as::uint8(&parts[1]), 1);
assert_eq!(bits_as::uint8(&parts[2]), 2);
assert_eq!(bits_as::uint8(&parts[3]), 6);
assert_eq!(bits_as::uint8(&parts[4]), 1);

let parts2 = scheme.split_bytes_at(8, [0xBA, 0x1C]);

assert_eq!(bits_as::int8(&parts2[0]), -4);
assert_eq!(bits_as::uint8(&parts2[1]), 0);
assert_eq!(bits_as::uint8(&parts2[2]), 0);
assert_eq!(bits_as::uint8(&parts2[3]), 0);
assert_eq!(bits_as::uint8(&parts2[4]), 0);

let scheme2 = Scheme::new([
    Field::aligned(23, -1, true),
    Field::aligned(0, -1, false),
    Field::bytes(-1, false),
    Field::signed(-1),
    Field::unsigned(-1),
    Field::unsigned(0),
    Field::unsigned(32),
    Field::bytes(4, false),
    Field::aligned(0, 8, false),
    Field::aligned(7, 8, true),
    Field::signed(-1),
    Field::unsigned(-1)
]);

let parts = scheme2.split_bytes_at(4, [0xBA, 0xDC, 0xFE, 0x10, 0x32]);

assert_eq!(bits_as::int32(&parts[0]), 0x0FEDCB);
assert_eq!(parts[1], Bits::empty());
assert_eq!(bits_as::vec_u8(&parts[2]), vec![0x42]);
assert_eq!(bits_as::vec_i32(&parts[3]), vec![6]);
assert_eq!(parts[4], Bits::empty());
assert_eq!(parts[5], Bits::empty());
assert_eq!(parts[6], Bits::zeros(32));
assert_eq!(parts[7], Bits::zeros(32));
assert_eq!(parts[8], Bits::empty());
assert_eq!(parts[9], Bits::zeros(56));
assert_eq!(parts[10], Bits::empty());
assert_eq!(parts[11], Bits::empty());