On Wed, Jun 12, 2019 at 11:27 PM Chris Angelico <rosuav@gmail.com> wrote:
> Yes, you would need some sort of syntactic parser. There are a couple
> of ways to go about it. One is to make use of Python's own tools, like
> the ast module; the other is to mandate that your specific syntax be
> "tidier" than the rest of the Python code, which would permit you to
> use a more naive and simplistic parser (even a regex).
Yep ... I just tried to use MacroPy3 to handle this but failed, seems
MacroPy3 does expect valid Python syntax in the first place for
anything else to happen. I also tried the raw ast module which seems
also the case. So it means if one want to use python ast module to
parse user input, the user input has to be valid python syntax (e.g.
no <==) at the first place. Seems this is a chicken-egg problem.
As I mentioned very early on in this seemingly-never-ending discussion,
there is a way to do things similar to what you want to do, by doing transformations
on the source code prior to execution (prior to constructing an AST).
Here's the link to the set of examples which I have done as demonstrations of this technique:
André Roberge
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