On Thu, Apr 2, 2020 at 3:16 PM Guido van Rossum email@example.com wrote:
Since last fall's core sprint in London, Pablo Galindo Salgado, Lysandros Nikolaou and myself have been working on a new parser for CPython. We are now far enough along that we present a PEP we've written:
Hopefully the PEP speaks for itself. We are hoping for a speedy resolution so we can land the code we've written before 3.9 beta 1.
If people insist I can post a copy of the entire PEP here on the list, but since a lot of it is just background information on the old LL(1) and the new PEG parsing algorithms, I figure I'd spare everyone the need of reading through that. Below is a copy of the most relevant section from the PEP. I'd also like to point out the section on performance (which you can find through the above link) -- basically performance is on a par with that of the old parser.
I think using a PEG parser is interesting, but I do have some questions related to what's to expect in the future for other people which have to follow the Python grammar, so, can you shed some light on this?
Does that mean that the grammar format currently available (which is currently specified in https://docs.python.org/3.8/reference/grammar.html) will no longer be updated/used?
Is it expected that other language implementations/parsers also have to move to a PEG parser in the future? -- which would probably be the case if the language deviates strongly off LL(1)