pyrlang 0.1.2

Python implemented on the BEAM, packaged with Erlang/OTP

Pyrlang

Pyrlang is Python implemented on the BEAM, primarily in Erlang/OTP.

The project goal is not to build a CPython package, a python -m runner, or a Python library that mimics Erlang. Pyrlang source is parsed, loaded, evaluated, interpreted, or compiled by BEAM-resident runtime code.

Current repository contents:

• SPEC.md: language and runtime semantics.
• WEB.md: Pyrunicorn WSGI target architecture.
• src/: BEAM-native Erlang runtime modules.
• test/: EUnit tests for the current runtime slice.
• bin/: BEAM-native escript entrypoints for pyrlang and pyrunicorn.
• include/: shared Erlang definitions.
• Makefile: plain erlc/erl build and test entrypoint.

Implemented foundation:

• Actor-local heaps and mutable container/object references.
• Message export/import with copied mutable values and cyclic object graphs. Native stdlib objects that close over actor-local state or BEAM resources are marked unsendable and surface as Pyrlang TypeError through source-level send().
• BEAM actor primitives: spawn, send, receive, selective receive, call/reply, source-level links, monitors, demonitoring, linked spawn, exit trapping, registration, source-level receive timeouts, and explicit atom-safe Erlang calls through erlang.apply.
• Parser/evaluator subset for expressions, assignments, functions, classes, methods, attributes, subscripts, decorators, if/elif/else, while, for, try/except/finally, with, yield, lambdas, boolean operators, membership, identity comparisons, simple slices, keyword/default arguments, *args/**kwargs, call expansion, range, and list/dict/set comprehensions.
• Literal support for None, booleans, integers, floats, strings, bytes, tuples, lists, dicts, and sets.
• Object model foundation: classes, instances, descriptors, bound methods, and C3 MRO, including super(), property, staticmethod, classmethod, and callable instances plus arithmetic/comparison special-method dispatch. Class suites execute supported Pyrlang statements including nested classes, imports, conditionals, loops, exception handlers, and context managers.
• Basic metaclass creation and inherited metaclass selection through class C(metaclass=...) and type(name, bases, attrs).
• Dynamic object helpers: getattr, setattr, hasattr, isinstance, issubclass, and type(obj) for Pyrlang instances.
• BEAM-backed open() for basic file read/write/close and context-manager use, with live file handles marked as actor-local unsendable resources.
• Actor-local module/package loading/imports from .py and __init__.py source files, with .pyr accepted as a legacy project-local extension, plus BEAM-native erlang, os, re, hashlib, hmac, secrets, contextvars, weakref, threading, importlib, datetime, decimal, logging, pathlib, http.cookies, urllib.parse, and email.utils modules, plus a minimal actor-backed sqlite3 DB-API surface.
• Pyrlang exception values with catch/raise flow, StopIteration, catchable attribute/subscript/operator errors, and bare raise re-raising the active exception inside exception handlers.
• Generator objects, the user-visible __iter__/__next__ protocol, and source-level mutable list/dict operations, including iter, list, tuple, dict, and set constructors.
• One-for-one supervisor foundation.
• Actor-backed SQLite access through an Erlang port to sqlite3, with connection-scoped transactions, DB-API connection/cursor objects marked as actor-local resources, and connection actor crashes mapped to DB-API operational errors.
• Pyrunicorn WSGI environ/worker/http/server foundation that loads Pyrlang module:callable apps inside worker actors, provides basic WSGI stream objects with sized and line reads, supports iterable response bodies and the start_response write callable including exc_info replacement before headers are sent, threads configured and socket-derived WSGI environ values such as SERVER_PORT and REMOTE_ADDR into Pyrlang-source apps, isolates worker module globals, returns 400 responses for malformed requests and 500 responses for app and worker failures, reads Content-Length bodies across TCP packets, serves over a real TCP socket with a round-robin worker pool, restarts crashed workers, and boots a small Pyrlang-source Django-shaped WSGI shim with a minimal middleware chain.
• BEAM-native bin/pyrlang and bin/pyrunicorn escript wrappers. pyrunicorn accepts --bind, --workers, --django-settings-module, and --path.
• pyrlang -m module ... executes a module or package __main__.py through the Pyrlang runtime and exposes arguments through the BEAM-native sys.argv.

Run the current verification suite:

make test

Build and refresh executable entrypoint bits:

make entrypoints

This repository implements the current scoped contracts in SPEC.md and WEB.md: Python-syntax Pyrlang source running on BEAM-resident runtime code, actor-backed runtime behavior, and Pyrlang-source WSGI on BEAM-native Pyrunicorn. Larger Python and Django compatibility areas remain outside the current scope until the specifications are expanded.