Is there an eBNF+PEG or similar grammar for the language parser that a more complete language reference can be generated from?
Does Lean have docstrings with embedded markup like Python?
The Python Language Reference:
https://docs.python.org/3/reference/
The Python Language Reference > 10. Full Grammar specification: https://docs.python.org/3/reference/grammar.html
LearnXinYminutes > Where X=Python: https://learnxinyminutes.com/docs/python/
In the language and then the docs, Python's collections.abc Abstract Base Classes did not initially exist. There's now a table of ABCs in the docs:
https://docs.python.org/3/library/collections.abc.html#colle...
In Python, they're not interfaces, they're ABCs.