markdown-it-py-rust (Rust mirror of executablebooks/markdown-it-py)

Stage-1 Rust mirror of executablebooks/markdown-it-py (MIT). Behavior-identical port of markdown_it/*.py exposed as the markdown_it._markdown_it extension module via PyO3, with thin markdown_it/*.py re-export shims preserving the original public API (MarkdownIt, Token, presets, plugins, CLI, ...).

Layout (publishable)

One implementation, two distributions:

• markdown-it-core/ — reusable pure-Rust core crate markdown-it-rust-core (crates.io). No Python dependency: rlib, cargo test clean. Rust consumers depend on this crate directly.
• src/ — thin PyO3 binding crate markdown-it-py-rust calling that same core. Ships on PyPI as distribution markdown-it-py-rust; the import name is unchanged (import markdown_it), so users swap the install with zero code changes: pip install markdown-it-py-rust instead of pip install markdown-it-py.
• markdown_it/ — Python shims (one per original module; tree.py, cli/, presets/, and utils.read_fixture_file stay verbatim Python).
• release.toml — release configuration (names, version, platforms, Python versions, publishing repo + workflow identity, license, upstream attribution). Read by rustsmith release-prep; see docs/RELEASE.md.

No redesign: same token stream, same plugin rule protocol, same HTML.

Porting boundary

Everything is ported to Rust except three host-callback seams (matching the original behavior exactly through the Host trait):

• mdurl (normalizeLink/normalizeLinkText) and linkify-it-py (md.linkify) stay Python packages, called through the GIL;
• plugin rule callables (Ruler.before/after/at/push, render-rule overrides, highlight) run as Python callbacks over the live core state;
• Token.meta supports JSON-shaped values (None/bool/int/float/str); arbitrary objects raise TypeError on assignment.

Install

pip install markdown-it-py-rust

from markdown_it import MarkdownIt
MarkdownIt().render("# hi")

Measured performance

No accepted optimizations yet (mirror baseline); re-run release-prep after run --stage optimize merges winners. Artifact hashes are intentionally absent here; see release-manifest.json.