fable-library 5.5.0

Fable library for Python

Fable Library for Python

This module is used as the Fable library for Python.

This document outlines the distribution strategy for the Fable Python target, which includes both Python code and Rust-based extensions for features like unsigned integers that aren't natively supported in Python.

The code should be annotated using type hints and statically type checked using pylance at strict setting.

The code should be formatted using the ruff formatter with default settings.

Fable Python Target Distribution Design

Design Goals

• Provide proper type support for F# (including uint8, etc.) and performance using Rust extensions
• Support cross-platform usage of libraries compiled with Fable
• Offer flexibility for library authors (bundled vs PyPI dependency)
• Minimize duplication while ensuring stability

Architecture

The system uses a two-tier architecture:

1. Python components - The main Fable library functionality
2. Rust extensions - Native code for performance and proper type support

Distribution Approach

The fable-library package will be available through two methods:

1. Bundled - Generated and included directly with compiled F# code
2. PyPI - Installable as a dependency with wheels for all major platforms

Library authors can choose which approach to use based on their distribution needs. Note that libraries made for distribution must use the PyPI approach since the bundled version will only work locally (single architecture).

Version Management

Major Versions

• Versions are aligned with main Fable releases and a new release will be generated for every tagged release
• Older versions for compatibility remain available through version pinning

Implementation Notes

1. All Rust extensions are compiled for multiple platforms during the PyPI package build