Trait Coding

pub trait Coding {
    type Value;
    type Decoder<'d>: Decoder<Value = Self::Value>
       where Self: 'd;
    type Encoder<'e>
       where Self: 'e;
    type Codeword: Copy + Sized + Sync;

    // Required methods
    fn bits_per_fragment(&self) -> u8;
    fn decoder(&self) -> Self::Decoder<'_>;
    fn encoder(&self) -> Self::Encoder<'_>;
    fn len_of(&self, code: Self::Codeword) -> u8;
    fn fragment_of(&self, code: Self::Codeword, index: u8) -> u8;
    fn remove_first_fragment_of(&self, code: &mut Self::Codeword) -> bool;
    fn code_of<'e, Q>(
        &self,
        encoder: &Self::Encoder<'e>,
        to_encode: &Q,
    ) -> Self::Codeword
       where Q: Borrow<Self::Value>;

    // Provided methods
    fn max_fragment_value(&self) -> u8 { ... }
    fn rev_fragment_of(&self, code: Self::Codeword, index: u8) -> u8 { ... }
    fn fragments_of(&self, code: Self::Codeword) -> FragmentsIterator<'_, Self>  { ... }
    fn is_code_empty(&self, code: Self::Codeword) -> bool { ... }
    fn first_fragment_of(&self, code: Self::Codeword) -> u8 { ... }
    fn extract_first_fragment_of(&self, code: &mut Self::Codeword) -> Option<u8> { ... }
    fn len_of_encoded<'e, Q>(
        &self,
        encoder: &Self::Encoder<'e>,
        to_encode: &Q,
    ) -> u8
       where Q: Borrow<Self::Value> { ... }
    fn fragments_of_encoded<'e, Q>(
        &self,
        encoder: &Self::Encoder<'e>,
        to_encode: &Q,
    ) -> FragmentsIterator<'_, Self> 
       where Q: Borrow<Self::Value> { ... }
}

A bijection between values and codewords. Codewords are sequences of fragments. Each fragment occupies constant number of bits.

Required Associated Types

type Value

Type of value.

type Decoder<'d>: Decoder<Value = Self::Value> where Self: 'd

Type of decoder. Decoder decodes a value for code given fragment by fragment.

type Encoder<'e> where Self: 'e

Type of encoder. Encoder maps values to their codes.

type Codeword: Copy + Sized + Sync

Type of codeword.

Required Methods

fn bits_per_fragment(&self) -> u8

Number of bits needed to store codeword fragment.

fn decoder(&self) -> Self::Decoder<'_>

Returns decoder that allows for decoding a value.

fn encoder(&self) -> Self::Encoder<'_>

Returns a map from values to their codewords.

fn len_of(&self, code: Self::Codeword) -> u8

Returns the length of code in fragments.

fn fragment_of(&self, code: Self::Codeword, index: u8) -> u8

Returns index-th fragment of code.

fn remove_first_fragment_of(&self, code: &mut Self::Codeword) -> bool

Removes the first fragment of the code and returns whether it is empty now.

fn code_of<'e, Q>( &self, encoder: &Self::Encoder<'e>, to_encode: &Q, ) -> Self::Codeword

where Q: Borrow<Self::Value>,

Returns code of the value to_encode.

Provided Methods

fn max_fragment_value(&self) -> u8

Maximum value of fragment.

fn rev_fragment_of(&self, code: Self::Codeword, index: u8) -> u8

Returns last index-th fragment of code.

fn fragments_of(&self, code: Self::Codeword) -> FragmentsIterator<'_, Self>

Returns iterator over code fragments.

fn is_code_empty(&self, code: Self::Codeword) -> bool

Returns whether the code is empty (has zero fragments).

fn first_fragment_of(&self, code: Self::Codeword) -> u8

Returns the first fragment of the code.

fn extract_first_fragment_of(&self, code: &mut Self::Codeword) -> Option<u8>

Extracts and returns the first fragment of the code or None if the code is already empty.

fn len_of_encoded<'e, Q>( &self, encoder: &Self::Encoder<'e>, to_encode: &Q, ) -> u8

where Q: Borrow<Self::Value>,

Returns the length (number of fragments) of code of the value to_encode. (this is the same value as code(to_encode).fragments, but code_len is faster for some encoders)

fn fragments_of_encoded<'e, Q>( &self, encoder: &Self::Encoder<'e>, to_encode: &Q, ) -> FragmentsIterator<'_, Self>

where Q: Borrow<Self::Value>,

Returns iterator over code fragments.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<Value: Hash + Eq + Clone> Coding for Coding<Value, BitsPerFragment>

type Value = Value

type Decoder<'d> = Decoder<'d, Value> where Value: 'd

type Encoder<'e> = HashMap<&'e Value, U8Code> where Value: 'e

type Codeword = U8Code

fn bits_per_fragment(&self) -> u8

fn decoder(&self) -> Self::Decoder<'_>

fn encoder(&self) -> Self::Encoder<'_>

fn len_of(&self, code: U8Code) -> u8

fn fragment_of(&self, code: Self::Codeword, index: u8) -> u8

fn rev_fragment_of(&self, code: Self::Codeword, index: u8) -> u8

fn remove_first_fragment_of(&self, code: &mut U8Code) -> bool

fn code_of<'e, Q>( &self, encoder: &Self::Encoder<'e>, to_encode: &Q, ) -> Self::Codeword

where Q: Borrow<Self::Value>,

Implementors

impl Coding for GeometricUnlimited

type Value = u16

type Decoder<'d> = GeometricUnlimitedDecoder

type Encoder<'e> = ()

type Codeword = U8Code