v0.18.0

Usability

• Reading now requires Seek. Attributes such as seek_from_start, seek_from_current, seek_from_end, and seek_rewind were added to be able to control the position of the reader before reading a field (#360)
• Support added for unit structs (#450)
• to_slice was added to write an to a slice (#461)

Performance

• The use of bits parsing is now an optional feature. If bit-level parsing is not useful for your application, you can disable it to get some performance benefits. (#446)
• Performance of read_all was improved (#441)

Enum improvements

• Added id_endian attribute to specify the endianness of id (#476)
• Support for bool literals in enum id attribute (#472)
• id_pat attribute was re-introduced (#454)

v0.17.0

Changes

• Bumped MSRV to 1.71 (#438)
• Add DekuWrite impl for [T] (#416)
• Add no-assert-string feature to remove panic string on failed assertion (#405)
• Add read_all attribute to read until reader.end() (#387)
• Changed edition to 2021 (#389)
• Refactored logging feature with massive usability increases (#352), (#355)
• Bumped the syn library to 2.0, which required replacing type for Enums with id_type (#386)

 #[derive(PartialEq, Debug, DekuRead, DekuWrite)]
-#[deku(type = "u8")]
+#[deku(id_type = "u8")]
 enum DekuTest {
     #[deku(id_pat = "_")]
     VariantC((u8, u8)),
 }

Updated Reader API

• Changed API of reading to use io::Read, bringing massive performance and usability improvements (#352)
• Changed the trait DekuRead to DekuReader

For example:

use std::io::{Seek, SeekFrom, Read};
use std::fs::File;
use deku::prelude::*;

#[derive(Debug, DekuRead, DekuWrite, PartialEq, Eq, Clone, Hash)]
#[deku(endian = "big")]
struct EcHdr {
    magic: [u8; 4],
    version: u8,
    padding1: [u8; 3],
}

let mut file = File::options().read(true).open("file").unwrap();
let ec = EcHdr::from_reader((&mut file, 0)).unwrap();

• The more internal (with context) read(..) was replaced with from_reader_with_ctx(..).
  With the switch to internal streaming, the variables deku::input, deku::input_bits, and deku::rest are now not possible and were removed.
  deku::reader is a replacement for some of the functionality.
  See examples/deku_input.rs for a new example of caching all reads.

Old:

#[derive(Debug, PartialEq, DekuRead, DekuWrite)]
struct DekuTest {
    field_a: u8,

    #[deku(
        reader = "bit_flipper_read(*field_a, deku::rest, BitSize(8))",
    )]
    field_b: u8,
}

fn custom_read(
    field_a: u8,
    rest: &BitSlice<u8, Msb0>,
    bit_size: BitSize,
) -> Result<(&BitSlice<u8, Msb0>, u8), DekuError> {

    // read field_b, calling original func
    let (rest, value) = u8::read(rest, bit_size)?;

    Ok((rest, value))
}

New:

#[derive(Debug, PartialEq, DekuRead, DekuWrite)]
struct DekuTest {
    field_a: u8,

    #[deku(
        reader = "bit_flipper_read(*field_a, deku::reader, BitSize(8))",
    )]
    field_b: u8,
}

fn custom_read<R: std::io::Read>(
    field_a: u8,
    reader: &mut Reader<R>,
    bit_size: BitSize,
) -> Result<u8, DekuError> {

    // read field_b, calling original func
    let value = u8::from_reader_with_ctx(reader, bit_size)?;

    Ok(value)
}

• With the addition of using Read, containing a byte slice with a reference is not supported:

Old

#[derive(PartialEq, Debug, DekuRead, DekuWrite)]
struct TestStruct<'a> {
    bytes: u8,

    #[deku(bytes_read = "bytes")]
    data: &'a [u8],
}

New

#[derive(PartialEq, Debug, DekuRead, DekuWrite)]
struct TestStruct {
    bytes: u8,

    #[deku(bytes_read = "bytes")]
    data: Vec<u8>,
}

• id_pat is now required to be the same type as stored id.
  This also disallows using tuples for storing the id:

Old:

#[derive(PartialEq, Debug, DekuRead, DekuWrite)]
#[deku(id_type = "u8")]
enum DekuTest {
    #[deku(id_pat = "_")]
    VariantC((u8, u8)),
}

New:

#[derive(PartialEq, Debug, DekuRead, DekuWrite)]
#[deku(id_type = "u8")]
enum DekuTest {
    #[deku(id_pat = "_")]
    VariantC {
        id: u8,
        other: u8,
    },
}

• The feature const_generics was removed and is enabled by default.

Updated Writer API

• Changed API of writing to use io::Write, bringing massive performance and usability improvements (#355)
• Changed the trait DekuWrite to DekuWriter
• The more internal (with context) write(..) was replaced with to_writer(..).
  With the switch to internal streaming, the variables deku::output are now not possible and were removed. deku::writer is a replacement for some of the functionality.

Old:

fn bit_flipper_write(
    field_a: u8,
    field_b: u8,
    output: &mut BitVec<u8, Msb0>,
    bit_size: BitSize,
) -> Result<(), DekuError> {
    // Access to previously written fields
    println!("field_a = 0x{:X}", field_a);

    // value of field_b
    println!("field_b = 0x{:X}", field_b);

    // Size of the current field
    println!("bit_size: {:?}", bit_size);

    // flip the bits on value if field_a is 0x01
    let value = if field_a == 0x01 { !field_b } else { field_b };

    value.write(output, bit_size)
}

#[derive(Debug, PartialEq, DekuRead, DekuWrite)]
struct DekuTest {
    field_a: u8,

    #[deku(
        writer = "bit_flipper_write(*field_a, *field_b, deku::output, BitSize(8))"
    )]
    field_b: u8,
}

New:

fn bit_flipper_write<W: Write>(
    field_a: u8,
    field_b: u8,
    writer: &mut Writer<W>,
    bit_size: BitSize,
) -> Result<(), DekuError> {
    // Access to previously written fields
    println!("field_a = 0x{:X}", field_a);

    // value of field_b
    println!("field_b = 0x{:X}", field_b);

    // Size of the current field
    println!("bit_size: {:?}", bit_size);

    // flip the bits on value if field_a is 0x01
    let value = if field_a == 0x01 { !field_b } else { field_b };

    value.to_writer(writer, bit_size)
}

#[derive(Debug, PartialEq, DekuRead, DekuWrite)]
struct DekuTest {
    field_a: u8,

    #[deku(
        writer = "bit_flipper_write(*field_a, *field_b, deku::writer, BitSize(8))"
    )]
    field_b: u8,
}

• Added DekuError::Write to denote io::Write errors

Bug fix

• Fix error for invalid deku_id generation on generic enum (#411)