Fix non-byteplay code in commit 8833ef... to support both Python 2 and Python 3 about enaml HOT 5 OPEN

Do you have any ideas on how to do that ?

from enaml.

If I remember correctly this part of changes is related to WIP-changes in parser.

I think the easiest way to go is to support enaml-syntax version the same as that of the package. I believe the amount of enaml code out there isn't that big, so if one wants to move to Python 3 it won't be a problem to convert enaml code too.

As of the way to achieve this. parser.py defines the syntax, so we can't implement support of both Python versions in one file. So basically one should take old version and name it for example _parser2.py, name new version _parser3.py and choose which module to import in parser.py based on Python version. Maybe there is more elegant way...

from enaml.

I will have to look at both versions but one way to make things easier to maintain may be to write the parser as a class (possible in pyparsing). This way we can have a base class handling common patterns and add more cases in a Python2 and Python3 subclasses. I will look into both and see what amount of code is duplicated to see whether or not this is pertinent.

from enaml.

Currently there is quite a large amount of common code, but it won't be the case when full Python 3 grammar would be supported. In source of Python there is explicit grammar of the language, and I suspect it was the source for original version of parser.py. You can compare grammars of different Python versions to estimate the amount of common grammar rules, which as I understand you consider putting in base class.

from enaml.

Thanks for the pointer. I will give it a look.

from enaml.