On Sun, 23 Aug 2020 at 02:42, Guido van Rossum
IMO this is just too large of a step to expect either redradrist or Marco Sulla to take.
You're quite right, I have proposed it to have an opinion by experts. Indeed I have no knowledge about how a parser works. This is why I asked if this is possible and desirable. Anyway, I was not thinking about a macro system, but about custom keywords. Maybe a macro is more simple, but was not my idea. My idea is to be able to delegate the parsing of a piece of code to a custom parser, defined in a third-party module. Cython, for example, uses its parser to compile Python code to C code. Cython uses custom keywords like cdef to speed up the code introducing C static typing. My idea and question is if it's possible to have something like this: from cython import * @int a = 0 About Jython and other implementations, as far as I know they can't use C extensions. Not without many troubles.