This repository focuses on adding new encoding/decoding schemes only.

Copilot MUST:

• Propose new codecs only
• Avoid refactoring unrelated code
• Avoid dependency changes unless strictly required for the codec
• Avoid stylistic or formatting changes

This project extends Python's codecs with many encoding/decoding schemes and a CLI tool. It already includes a wide variety of bases, ciphers, compression, and niche encodings.

When adding a new encoding, follow the guideline in the documentation at docs/pages/howto.md.

• Pure Python preferred
• No heavy dependencies
• Deterministic transformations only
• Reversible encoding required unless explicitly documented

Every new codec:

• SHOULD include a list of __examples__ that tells the automated tests what encoding/decoding transformations need to be verified ; it this cannot be made, unit tests (encode/decode roundtrip) SHALL be provided in tests/test_manual.py
• Edge cases (empty input, binary data if applicable), either in the __examples__ list or in the explicit tests in tests/test_manual.py

Each codec SHALL comply with the following structure:

```python
# -*- coding: UTF-8 -*-
"""{{codec_long_name}} Codec - {{codec_short_name}} content encoding.

{{codec_description}}

This codec:
- en/decodes strings from str to str
- en/decodes strings from bytes to bytes
- decodes file content to str (read)
- encodes file content from str to bytes (write)

Reference: {{codec_source_hyperlink}}
"""
from ..__common__ import *


__examples__ = {<<dictionary of examples with, as keys, a special format detailed hereafter and, as values, a dictionary mapping source to destination values (see sectino _Self-generated tests_)>>}
<<optional list of valid codec names to be used with the guessing mode (see _Codec names for the guessing mode_), in format "__guess__ = [...]">>]


<<constants here, including ENCMAP if the codec is a simple mapping (see section _Case 2: Encoding map_)>>
<<functions here, if the codec requires some additional logic, i.e. when it is not a mapping (see section _Case 1: Generic encoding definition_)>>


<<put the right add function (see section _Which `add` function ?_) here with its relevant parameters (see section _Generic arguments_)>>
```

In this template, {{ ... }} enclosures indicate codec's properties and << ... >>``enclosures indicate placeholder actions referring to steps from the documentation about how to make a codec at docs/pages/howto.md`.

When asked to add a codec, Copilot should:

1. Briefly justify the encoding (1–2 lines)
2. Provide full implementation (according to section Adding a new codec to codext of the documentation at docs/pages/howto.md)
3. Provide tests (according to section Self-generated tests)
4. Add it to the README.md of the repository
5. Propose the update of the documentation (under the relevant page for the category of codec)

• No refactoring
• No performance optimization passes
• No linting-only changes
• No CI/CD changes