On Wed, May 9, 2018 at 6:16 AM, Mikhail V <mikhail...@gmail.com> wrote: > Also I don't know what kind of human thinks that this: > a + b > is two elements "a" and "+ b" > What is "+ b"?
Unary plus applied to whatever value 'b' is. > And who writes "- b" with a space in unary minus? > I don't. Nobody does. Is it allowed? yes. no problem. You're making a syntax proposal. That means it has to cope with all the vagaries of syntax, including things that you think "nobody does". >> - the first one is unambiguous while the second is ambiguous; > > I think it's time to reveal what exactly you mean here. > In the above example there is nothing ambigious. > At least not for someone who is Ok with basic editing > skills. There are things that are ambiguous to the Python syntax parser. If you want to create a completely new syntax that happens to incorporate some Python expressions, that's not a problem. It isn't a Python syntax enhancement, it is a completely separate file format, and you can do what you like with that. You can use tabs to separate tokens, eval() those tokens to figure out the actual value, and then build the resulting data structure according to your rules. And it's 100% acceptable to demand a stricter form of Python syntax within your tokens (eg "no tabs allowed"), because it's your own data file. And, even better: You can write code to parse this, without needing approval from the core devs. The code you write doesn't have to wait until Python 3.8 is released (two years from now); it can run on existing interpreters. All the advantages are on your side. ChrisA -- https://mail.python.org/mailman/listinfo/python-list